HonAlg2AnsKey

May 13, 2018 | Author: pn11x2 | Category: Rational Number, Equations, Slope, Function (Mathematics), Elementary Mathematics
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Answer Key Transparencies Provides transparencies with answers for each lesson in the Student Edition

ISBN 0-07-828001-X

90000

9 780078 280016

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Chapter 1 Solving Equations and Inequalities Lesson 1-1 Expressions and Formulas Pages 8–10 1. First, find the sum of c and d. Divide this sum by e. Multiply the quotient by b. Finally, add a.

2. Sample answer:

3. b; The sum of the cost of adult and children tickets should be subtracted from 50. Therefore, parentheses need to be inserted around this sum to insure that this addition is done before subtraction.

4. 72

5. 6

6. 23

7. 1

8. 2

9. 119

10. 0

11. 23

12. 18

13. $432

14. $1875

15. $1162.50

16. 20

17. 3

18. 29

19. 25

20. 54

21. 34

22. 19

23. 5

24. 11

25. 31

26. 7

27. 14

28. 15

29. 3

30. 52

31. 162

32. 15.3

33. 2.56

34. 7

35. 25

1 3

36. about 1.8 lb

37. 31.25 drops per min

38. 3.4

39. 2

40. 45

©Glencoe/McGraw-Hill

14  4 5

1

Algebra 2

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41. 4.2

42. 5.3

43. 4

44. 75

45. 1.4

46. 4

47. 8

48. 36.01

49. 2

y5 2 b 2

50.  a

1 6

51. 16

52. 30

53. $8266.03

54. 400 ft

55. Sample answer: 44441 44442 14  4  42  4  3 4  14  42  4  4 14  4  42  4  5 14  42  4  4  6 44  4  4  7 14  42  14  42  8 44449 144  42  4  10

56. Nurses use formulas to calculate a drug dosage given a supply dosage and a doctor’s drug order. They also use formulas to calculate IV flow rates. Answers should include the following. • A table of IV flow rates is limited to those situations listed, while a formula can be used to find any IV flow rate. • If a formula used in a nursing setting is applied incorrectly, a patient could die.

57. C

58. D

59. 3

60. 4

61. 10

62. 13

63. 2

64. 5

65.

2 3

©Glencoe/McGraw-Hill

66.

2

6 7

Algebra 2

Chapter 1

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Lesson 1-2 1a. 1b. 1c. 1d. 1e. 1f.

Sample Sample Sample Sample Sample Sample

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Properties of Real Numbers Pages 14–18

answer: 2 answer: 5 answer: 11 answer: 1.3 answer: 12 answer: 1.3

2. A rational number is the ratio of two integers. Since 13 is 13 not an integer, is not a 2 rational number.

3. 0; Zero does not have a multiplicative inverse since

4. Z, Q, R 1 0

is undefined. 5. N, W, Z, Q, R

6. Q, R

7. Multiplicative Identity

8. Associative Property () 1 8

10. 8, 

9. Additive Identity 1 3

2 3

11.  , 3

12. 1.5,

13. 2x  4y

14. 13p

15. 3c  18d

16. 17a  1

17. 1.5(10  15  12  8  19  22  31) or 1.5(10)  1.5(15)  1.5(12)  1.5(8)  1.5(19)  1.5(22)  1.5(31)

18. $175.50

19. W, Z, Q, R

20. Q, R

21. N, W, Z, Q, R

22. Q, R

23. I, R

24. Z, Q, R

25. N, W, Z, Q, R

26. I, R

27. Q, R; 2.4, 2.49, 2.49, 2.49, 2.9

28. Additive Inverse

29. Associative Property ()

30. Additive Identity

31. Associative Property ()

32. Commutative Property ()

33. Multiplicative Inverse

34. Distributive

35. Multiplicative Identity

36. 0

37. m; Additive Inverse

38.

©Glencoe/McGraw-Hill

3

1 ; m

Multiplicative Inverse Algebra 2

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39. 1

40. natural numbers

41. 12 units

42. The square root of 2 is irrational and therefore cannot be described by a natural number.

1 10

43. 10; 

44. 2.5; 0.4

45. 0.125; 8

46.

5 ; 8



3 5

4 3 3 4

8 5 5 23

47.  ,

48. 4 , 

49. 3a  2b

50. 10x  2y

51. 40x  7y

52. 11m  10a

53. 12r  4t

54. 32c  46d

55. 3.4m  1.8n

56. 4.4p  2.9q

57. 8  9y

58.

59. true

60. false; 3

61. false; 6

62. true

63. 6.5(4.5  4.25  5.25  6.5  5) or 6.5(4.5)  6.5(4.25)  (6.5)5.25  6.5(6.5)  6.5(5)

64. 3.6; $327.60

©Glencoe/McGraw-Hill

4

9 x 10



19 y 6

Algebra 2

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65. 3 a2 b  2 a1 b 1 4

1 8

66. 50(47  47); 50(47)  50(47)

 3 a2  b  2 a1  b 1 4

 

1 8 Def. of a mixed number 1 1 3 122  3 a b  2 112  2 a b 4 8 Distributive 3 1 6 2 Multiply. 4 4

3 1  4 4 3 1 8  4 4 1 3 8a  b 4 4

Comm. ()

 8  1 or 9

Add.

62

Add. Assoc. ()

67. 4700 ft2

68. $113(0.36  0.19); $113(0.36)  $113(0.19)

69. $62.15

70. Yes;    7;dividing 2 2 2 by a number is the same as multiplying by its reciprocal.

71. Answers should include the following. • Instead of doubling each coupon value and then adding these values together, the Distributive Property could be applied allowing you to add the coupon values first and then double the sum.

72. B

©Glencoe/McGraw-Hill

68

5

6

8

Algebra 2

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• If a store had a 25% off sale on all merchandise, the Distributive Property could be used to calculate these savings. For example, the savings on a $15 shirt, $40 pair of jeans, and $25 pair of slacks could be calculated as 0.25(15)  0.25(40)  0.25(25) or as 0.25(15  40  25) using the Distributive Property. 73. C

74. true

75. False; 0  1  1, which is not a whole number.

76. true

2 3

77. False; 2  3  , which is not

78. 9

a whole number. 79. 6

80. 5

81. 2.75

82. 358 in2

83. 11

84.

85. 4.3

86. 36

7 10

Chapter 1 Practice Quiz 1 Page 18 1. 14

2. 9

3. 6

4. 1

5. 2 amperes

6. Q, R

7. N, W, Z, Q, R

8. Additive Inverse

6 7 7 6

9.  ,

©Glencoe/McGraw-Hill

10. 50x  64y

6

Algebra 2

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Lesson 1-3 Solving Equations Pages 24–27 1. Sample answer: 2x  14

2. Sometimes true; only when the expression you are dividing by does not equal zero.

3. Jamal; his method can be confirmed by solving the equation using an alternative method.

4. 5  4n

C C C 9 cC 5



5 1322 9 5 1322 d 9

9 C 5



5 1F  322 9 5 5 F  1322 9 9 5 F 9

F

 32  F

5. 2n  n3

6. Sample answer: 9 times a number decreased by 3 is 6.

7. Sample answer: 5 plus 3 times the square of a number is twice that number.

8. Reflexive Property of Equality 10. 21

9. Addition Property of Equality 11. 14

12. 4

13. 4.8

14. 1.5

15. 16

16. y 

17. p 

I rt

9  2n 4

18. D

19. 5  3n

20. 10n  7

21. n 2  4

22. 6n3

23. 519  n2

24. 21n  82

25.

a

26. 1n  72 3

n 2 b 4

©Glencoe/McGraw-Hill

7

Algebra 2

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27. 2rh  2r 2

28. 2r 1h  r 2

29. Sample answer: 5 less than a number is 12.

30. Sample answer: Twice a number plus 3 is 1.

31. Sample answer: A number squared is equal to 4 times the number.

32. Sample answer: Three times the cube of a number is equal to the number plus 4.

33. Sample answer: A number divided by 4 is equal to twice the sum of that number and 1.

34. Sample answer: 7 minus half a number is equal to 3 divided by the square of x.

35. Substitution Property ()

36. Subtraction Property ()

37. Transitive Property ()

38. Addition Property ()

39. Symmetric Property ()

40. Multiplication Property ()

41. 7

42. 8

43. 3.2

44. 2.5

45.

3 4

1 12

46. 

47. 8

48. 11

49. 7

50.

51. 1

52. 12

53.

1 4

55. 

2 3

54. 19 10 17

55 2

56.

r

58. a 

57.

d t

59.

3V r 2

h

61. b 

x 1c  32 a

2

b 2x

60.

2A h

62.

4x 1x

ab y

63. n  number of games; 2(1.50)  n(2.50)  16.75; 5

64. s  length of a side; 8s  124, 15.5 in.

65. x  cost of gasoline per mile; 972  114  105  7600x  1837; 8.5¢/mi

66. n  number of students that can attend each meeting; 2n  3  83; 40 students

©Glencoe/McGraw-Hill

8

Algebra 2

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67. a  Chun-Wei’s age; a  (2a  8)  (2a  8  3)  94; Chun-Wei: 15 yrs old, mother: 38 yrs old, father: 41 yrs old

68. c  cost per student; 50 50130  c2  1452  5 1800; $3

69. n  number of lamps broken; 12(125)  45n  1365; 3 lamps

70. h  height of can A;

71. 15.1 mi/month

72. Central: 690 mi.; Union: 1085 mi

73. The Central Pacific had to lay their track through the Rocky Mountains, while the Union Pacific mainly built track over flat prairie.

74. $295

75. the product of 3 and the difference of a number and 5 added to the product of four times the number and the sum of the number and 1

76. To find the most effective level of intensity for your workout, you need to use your age and 10-second pulse count. You must also be able to solve the formula given for A. Answers should include the following. • Substitute 0.80 for I and 27 for P in the formula I  6  P  1220  A2 and solve for A. To solve this equation, divide the product of 6 and 28 by 0.8. Then subtract 220 and divide by 1. The result is 17.5. This means that this 1 person is 17 years old.

11.22 2h  122 23; 8 units 1 3

2

©Glencoe/McGraw-Hill

9

Algebra 2

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• To find the intensity level for different values of A and P would require solving a new equation but using the same steps as described above. Solving for A would mean that for future calculations of A you would only need to simplify an expression, 220 

6P , I

rather

than solve an equation. 77. B

78. D

79. 6x  8y  4z

80. 11a  8b

81. 6.6

82. 7.44

83. 105 cm2

84. 5

85. 3

86. 2.5 1 4

87. 

88. 3x

89. 5  6y

Lesson 1-4

Solving Absolute Value Equations Pages 30–32

1. 0 a 0  a when a is a negative number and the negative of a negative number is positive.

2a. 0 x 0  4 2b. 0 x  6 0  2 4. Sample answer: 0 4  6 0 ; 2

3. Always; since the opposite of 0 is still 0, this equation has only one case, ax  b  0. The solution is

b . a

6. 9

5. 8

8. 521, 136

7. 17

10. 511, 296

9. 518, 126

11. 532, 366 ©Glencoe/McGraw-Hill

12.  10

Algebra 2

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13. 586

14. 0 x  160 0  2

15. least: 158 F; greatest: 162 F

16. 162 F; This would ensure a minimum internal temperature of 160 F.

17. 15

18. 24

19. 0

20. 4

21. 3

22. 13

23. 4

24. 7.8

25. 9.4

26. 5

27. 55

28. 22

29. {8, 42}

30. 512, 306

33. 52, 166

34.

32. 528, 206

31. 545, 216

35.

3 e f 2

37.

e 2,

e 2,

16 f 3



36.  38. 54, 16

9 f 2

39. 

40. 

41. {5, 11}

42. {3, 15}

43.

11 e , 3

3 f

44.

5 f 3

46. 546

45. {8}

48. 0 x  16 0  0.3; heaviest: 16.3 oz, lightest: 15.7 oz

47. 0 x  200 0  5; maximum: 205 F; minimum: 195 F 49. 0 x  13 0  5; maximum: 18 km, minimum: 8 km

50. sometimes; true only if a 0 and b 0 or if a 0 and b 0

51. sometimes; true only if c 0

©Glencoe/McGraw-Hill

e 3,

52. Answers should include the following. • This equation needs to show that the difference of the estimate E from the originally stated magnitude of 6.1 could be plus 0.3 or 11

Algebra 2

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minus 0.3, as shown in the graph below. Instead of writing two equations, E  6.1  0.3 and E  6.1  0.3, absolute value symbols can be used to account for both possibilities, 0 E  6.1 0  0.3. 0.3 units 5.6

5.7

5.8

5.9

6.0

0.3 units 6.1

6.2

6.3

6.4

6.5

6.6

6.7

• Using an original magnitude of 5.9, the equation to represent the estimated extremes would be 0 E  5.9 0  0.3. 54. A

53. B

55. 0 x  1 0  2  x  4; 0 x  1 0  2  1x  42

56. x  1  2  x  4; x  1  2  x  4; x  1  2  x  4; x  1  2  x  4

57. 51.56

58. 8

59. 21n  112 61.

60. 5n 2

16 3

62. 2

63. 14

64. Commutative Property ()

65. Distributive Property

66. Multiplicative Inverse

67. Additive Identity

68. false; 23

69. true

70. true

71. false; 1.2

72.

73. 364 ft2

74. 2

75. 8

76. 2

77.

2 3

1 1x 2

 321x  52

78. 6 3 4

79. 

©Glencoe/McGraw-Hill

12

Algebra 2

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Lesson 1-5 Solving Inequalities Pages 37–39 2. Sample answer: 2n  6

1. Dividing by a number is the same as multiplying by its inverse.

4. 5a 0 a 1.56 or 1 , 1.52

3. Sample answer: x2 x1

⫺2

5 3

0

1

2

⫺2

3

7. 5y 0 y  66 or 16,  2

2

⫺6

17. 5x 0 x 76 or 1 , 72

24

26

⫺4

⫺6

©Glencoe/McGraw-Hill

⫺5

⫺4

⫺3

⫺8

⫺6

⫺4

⫺2

0

10 11 12 13 14 15 16 17 18 19 20 21

18. 5d 0 d  86 or 18,  2 ⫺10

28

⫺8

⫺6

⫺4

⫺2

0

20. 5p 0 p 36 or 1 , 34 ⫺6

30

21. 5k 0 k 3.56 or 33.5,  2 ⫺7

8

16. 5b 0 b 186 or 1 , 184

19. 5g 0 g 276 or 1 , 274 22

6

14. at least 92

⫺1 0 1 2 3 4 5 6 7 8 9 10

20

4

4

15. 5n 0 n 116 or 311,  2 ⫺8

2

12. 12n  36; n  3

13. 2n  3 5; n 4

⫺14 ⫺12 ⫺10

3

⫺30 ⫺28 ⫺26 ⫺24 ⫺22 ⫺20

11. all real numbers or 1 ,  2 0

2

10. 5n 0 n 246 or 1 , 244

8 9 10 11 12 13 14 15 16 17 18 19

⫺2

0

⫺10

9. 5p 0 p  156 or 115,  2

⫺4

1

8. 5w 0 w 76 or 1 , 72

⫺1 0 1 2 3 4 5 6 7 8 9 10

⫺6

0

6. 5c 0 c 36 or 3 3,  2

5. e x ` x f or a , d f 5 3

⫺1

⫺4

⫺2

0

2

4

22. 5y 0 y 56 or 1 , 52

⫺2

⫺4

13

⫺2

0

2

4

Algebra 2

6

Chapter 1

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23. 5m 0 m  46 or 14,  2 ⫺6

⫺4

⫺2

0

2

24. e b ` b f or c  b 2 3

4

⫺1

⫺2

0

2

4

⫺2

6

27. 5n 0 n 1.756 or 3 1.75,  2 0

0.5

1

1.5

2

2.5

⫺7

20

⫺2

⫺4

⫺2

0

0

2

4

6

or a ,  b 1 20

⫺1 ⫺ 3 ⫺ 1 4

20

1 20

20

2.0

2.2

2.4

2.6

2.8

5 7

4

5 7

0 1 2 3 4 5 6 1 8 9 10 11

1 5

1 5

3 5

⫺6

1

⫺4

⫺2

0

2

6

⫺4

⫺2

0

2

4

⫺4

⫺3

⫺2

3 2

⫺1

0

40. no more than 14 rides

41. n  8  2; n  6

42. 4n 35; n 8.75

1 n 2

4

3 2

39. at least 25 h

43.

7 7

38. e n ` n  f or a ,  d

37.  ⫺6

7 7

36. 5p 0 p  06 or 10,  2

35. e y ` y f or a , b 1 5

3.0

34. e a ` a f or c ,  b 7 7 7 7 7 7

3 5

3 20

32. 5z 0 z  2.66 or 12.6,  2

2

2

1 5

8

⫺20 ⫺18 ⫺16 ⫺14 ⫺12 ⫺10

33. 5g 0 g 26 or 1 , 22 ⫺6

1

30. 5c 0 c  186 or 118,  2

31. 5d 0 d 56 or 35,  2 ⫺4

2

1 f 20

⫺286 ⫺284 ⫺282 ⫺280 ⫺278 ⫺276

⫺6

0

28. ew ` w  

29. 5x 0 x 2796 or 1 , 2792

⫺8

0

26. 5r 0 r 66 or 1 , 64

25. 5t 0 t 06 or 1 , 04 ⫺4

2 3

 7 5; n 24

44. 3n  1 16; n  5 n 2

46. n  9 ; n 18

45. 21n  52 3n  11; n 1 17

47. 217m2 17; m , at least 14 2 child-care staff members ©Glencoe/McGraw-Hill

1

48. $24,000  0.015130,500n2

40,000 14

Algebra 2

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85  91  89  94  s 5

90

49. n 34.97; She must sell at least 35 cars.

50.

51. s 91; Ahmik must score at least 91 on her next test to have an A test average.

52a. It holds only for or ; 2  2. 52b. 1 2 but 2  1 52c. For all real numbers a, b, and c, if a b and b c then a c.

53. Answers should include the following. • 150 400 • Let n equal the number of minutes used. Write an expression representing the cost of Plan 1 and for Plan 2 for n minutes. The cost for Plan 1 would include a $35 monthly access fee plus 40¢ for each minute over 150 minutes or 35  0.41n  1502. The cost for Plan 2 for 400 minutes or less would be $55. To find where Plan 2 would cost less than Plan 1 solve 55 35  0.41n  1502 for n. The solution set is 5n 0 n  2006, which means that for more than 200 minutes of calls, Plan 2 is cheaper.

54. D

55. D

56. x  3

57. x 2

58. x 1

59. 514, 206

60.

5 11 e , f 4 4

61. 

62. b  online browsers each year; 6b  19.2  106.6; about 14.6 million online browsers each year

63. N, W, Z, Q, R

64. Q, R

©Glencoe/McGraw-Hill

15

Algebra 2

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66. 4.25(5.5  8); 4.25(5.5)  4.25(8)

65. I, R 67. 57, 76 69.

e 4,

68. 513, 236 70. 511, 256

4 f 5



71. 511, 16

72. 518, 106

Chapter 1 Practice Quiz 2 Page 39 2s t2

g

1. 0.5

2.

3. 14

4. e , 5 f 19 3

5. e m ` m  f or a ,  b 4 9

⫺2 9

0

4 9

2 9

4 9

2 3

8 1 9

Lesson 1-6 Solving Compound and Absolute Value Inequalities Pages 43–46 1. 5 c 15

2. Sample answer: x 3 and x2 4. 0 n 0 8

3. Sabrina; an absolute value inequality of the form 0 a 0  b should be rewritten as an or compound inequality, a  b or a b.

⫺12

5. 0 n 0  3 ⫺6

⫺4

7. 0 n 0 2

⫺2

0

2

⫺4

0

4

8

6. 0 n 0 4

4

8. 5y 0 y  4 or y 16 ⫺4

©Glencoe/McGraw-Hill

⫺8

16

⫺2

0

2

4 Algebra 2

6 Chapter 1

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9. 5d 0 2 d 36 ⫺4

⫺2

0

10. 5a 0 a 5 or a 56 2

4

11. 5g 0 13 g 56 ⫺16 ⫺12

⫺8

⫺4

0

⫺8

6

⫺2

⫺2

4

0

2

4

8

6

12

8

c

0

2

4

6

16. 0 n 0 7

⫺8

⫺4

0

4

8

12

⫺4

⫺2

0

2

4

6

⫺8

⫺4

0

4

8

12

17. 0 n 0 4 19. 0 n 0  8 21. 0 n 0  1

4

8

12

⫺8

⫺4

0

4

8

12

⫺1.4 ⫺1.2

0

1.2

1.4

1.6

4

6

8

2

4

6

2

4

6

24. 0 n 0 6

0

4

29. 5x 0 2 x 46 0

2

31. 5f 0 7 f 56

26. 0 n  1 0 3

28. 5t 0 1 t 36 8

4

12

0

⫺4

⫺2

2

0

32. all real numbers

⫺8

⫺6

⫺4

⫺2

0

⫺8

⫺4

0

4

8

12

⫺4

⫺2

0

2

4

6

33. 5g 0 9 g 96

⫺2

30. 5c 0 c 2 or c 16

6

⫺10

⫺4

⫺2

0

34. 5m 0 m 4 or m 46 ⫺4

⫺2

0

2

4

6

⫺8

⫺4

0

4

8

12

36. 5y 0 7 y 76

35. 

©Glencoe/McGraw-Hill

0

22. 0 n 0 5

27. 5p 0 p 2 or p 86

⫺2

⫺4

20. 0 n 0 1.2

25. 0 n  1 0  1 ⫺4

⫺8

18. 0 n 0 6

23. 0 n 0 1.5

⫺4

4

14. 55 60; 343.75 c 6.25 375; between $343.75 and $375

15. 0 n 0 5

⫺8

0

12. 5k 0 3 k 76

13. all real numbers ⫺4

⫺4

17

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Page 18 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-01:

38. 5r 0 3 r 46

37. 5b 0 b  10 or b 26 ⫺4

0

4

8

12

16

39. e w `  w 1 f 7 3

⫺2

⫺1

0

43.

⫺2

en ` n



0

1

0

⫺2

0

2

4

6

⫺4

⫺2

0

2

4

6

0

2

4

6

40.  1

42. 5n 0 n 06

41. all real numbers ⫺4

⫺4

2

4

6

⫺4

⫺2

44. 5n 0 n  1.56

7 f 2 2

3

4

⫺2

5

45. 6.8 x 7.4

⫺1

0

1

2

3

46. 45 s 65

47. 45 s 55

48. 0 t  98.6 0 8; 5b 0 b  106.6 or b 90.66

49. 108 in. L  D 130 in.

50. 84 in. L 106 in.

51. a  b  c, a  c  b, bca

52. a  b c a  b 54. Compound inequalities can be used to describe the acceptable time frame for the fasting state before a glucose tolerance test is administered to a patient suspected of having diabetes. Answers should include the following. • Use the word and when both inequalities must be satisfied. Use the word or when only one or the other of the inequalities must be satisfied. • 10 h 16

53a. ⫺4

⫺2

0

2

4

6

⫺4

⫺2

0

2

4

6

⫺4

⫺2

0

2

4

6

53b. 53c. 53d. 3 0 x  2 0 8 can be rewritten as 0 x  2 0  3 and 0 x  2 0 8. The solution of 0 x  2 0  3 is x  1 or x 5. The solution of 0 x  2 0 8 is 10 x 6. Therefore, the union of these two sets is 1x  1 or x 52

©Glencoe/McGraw-Hill

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Page 19 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-01:

and 110 x 6). The union of the graph of x  1 or x 5 and the graph of 10 x 6 is shown below. From this we can see that solution can be rewritten as 110 x 52 or 11 x 62. ⫺12

⫺8

⫺4

0

4

• 12 hours would be an acceptable fasting state for this test since it is part of the solution set of 10 h 16, as indicated on the graph below. 8 9 10 11 12 13 14 15 16 17 18 19

8

55. x  5 or x 6

56. D

57.

58. 2 x 3

59. 15x  2 32 or 15x  2 32; 5x 0 x 0.2 or x 16

60. abs12x  62  10; 5x  x 2 or x  86

61. d 6 or 36,  2 ⫺8

⫺6

⫺4

⫺2

0

⫺2

0

2

⫺4

2

63. n 1 or 1 , 12 ⫺4

62. x 4 or 1 , 42

4

⫺2

0

2

4

6

64. 0 x  587 0  5; highest: 592 keys, lowest: 582 keys 6

66. 511, 46

65. {10, 16} 67. 

68. Addition Property of Equality

69. Symmetric Property ()

70. Transitive Property of Equality

71. 3a  7b

72. 2m  7n  18

73. 2

74. 92

75. 7

©Glencoe/McGraw-Hill

19

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Chapter 2 Linear Relations and Functions Lesson 2-1 Relations and Functions Pages 60–62 2. Sample answer:

1. Sample answer: {(4, 3), (2, 3), (1, 5), (2, 1)}

y

x

O

3. Molly; to find g(2a), replace x with 2a. Teisha found 2g(a), not g(2a).

4. yes

5. yes

6. no

7. D  {7}, R  {1, 2, 5, 8}, no

8. D  {3, 4, 6}, R  {2.5}, yes y

(7, 8)

y

(7, 5)

(4, 2.5) (3, 2.5)

(6, 2.5)

(7, 2)

x

O O

(7, 1)

x

10. D  5x 0 x  06, R  all reals, no

9. D  all reals, R  all reals, yes

y

y

x  y2 O

x

O

x

y  2x  1

12. 7

11. 10

©Glencoe/McGraw-Hill

20

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13. D  {70, 72, 88}, R  {95, 97, 105, 114}

14. {(88, 97), (70, 114), (88, 95), (72, 105)}

15. Record High Temperatures

16. No; the domain value 88 is paired with two range values.

115

July

110 105 100 95 0

70 80 January

90

17. yes

18. no

19. no

20. yes

21. yes

22. no

23. D  {3, 1, 2}, R  {0, 1, 5}; yes

24. D  {3, 4, 6}, R  {5}; yes y

y

(3, 5) (4, 5)

(1, 5)

(6, 5)

(2, 1) (3, 0)

x

O

x

O

26. D  {3, 4, 5, 6}, R  {3, 4, 5, 6}; yes

25. D  {2, 3}, R  {5, 7, 8}; no (2, 8)

y

(3, 7)

y (5, 6) (3, 4)

(2, 5)

(6, 5)

(4, 3) O

©Glencoe/McGraw-Hill

x

O

21

x

Algebra 2

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Page 22 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

27. D  {3.6, 0, 1.4, 2}, R  {3, 1.1, 2, 8}; yes

28. D  {2.5, 1, 0}, R  {1, 1}; no y

y (3.6, 8)

(2.5, 1) (1, 1) (0, 1)

x

O (1, 1)

(1.4, 2)

x O (0, 1.1) (2, 3)

30. D  all reals, R  all reals; yes

29. D  all reals, R  all reals; yes

y

y

y  3x x

O

x

O

y  5x

31. D  all reals, R  all reals; yes

32. D  all reals, R  all reals; yes y

y

O O

x

x

y  7x  6

y  3x  4

©Glencoe/McGraw-Hill

22

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Page 23 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

34. D  5x 0 x  36, R  all reals; no

33. D  all reals, R  5y 0 y  06, yes y

y

O

yx

x

2

x  2y 2  3

x

O

36. D  {47, 48, 52, 56}, R  {145, 147, 148, 157, 165}

35. American League Leaders 170 165 RBI

160 155 150 145 140 0

48

50

52

54

56

HR

37. No; the domain value 56 is paired with two different range values.

38. {(1997, 39), (1998, 43), (1999, 48), (2000, 55), (2001, 61), (2002, 52)}

39.

40. D  {1997, 1998, 1999, 2000, 2001, 2002}, R  {39, 43, 48, 52, 55, 61}

Stock Price 70 60 Price ($)

50 40 30 20 10 0 1996

1998

2000 2002 Year

2004

42. {(1987, 12), (1989, 13), (1991, 11), (1993, 12), (1995, 9), (1997, 6), (1999, 3)}

41. Yes; each domain value is paired with only one range value.

©Glencoe/McGraw-Hill

23

Algebra 2

Chapter 2

PQ245-6457F-P02[020-055].qxd

43.

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Page 24 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

44. D  {1987, 1989, 1991, 1993, 1995, 1997, 1999}, R  {3, 6, 9, 11, 12, 13}

30+ Years of Service Representatives

14 12 10 8 6 4 2 0

’87

’91 ’95 Year

’99

45. Yes; no; each domain value is paired with only one range value so the relation is a function, but the range value 12 is paired with two domain values so the function is not one-to-one.

46. 14

47. 6

48. 

49. 3

50. 3a  5

51. 25n 2  5n

52. 4

53. 11

54. 39

55. f(x)  4x  3

56. Relations and functions can be used to represent biological data. Answers should include the following. • If the data are written as ordered pairs, then those ordered pairs are a relation. • The maximum lifetime of an animal is not a function of its average lifetime.

57. B

58. C

59. discrete

60. continuous

61. discrete

62. continuous

65. 5x 0 x  5.16

66. $2.85

2 9

63. 5y 0 8  y  66

©Glencoe/McGraw-Hill

64. 5m 0 4  m  66

24

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Page 25 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

67. $29.82

68. 43

69. 31a  10b

70. 1

71. 2

72. 6

73. 15

Lesson 2-2 Linear Equations Pages 65–67 2. 5, 2

1. The function can be written as 1 2

f(x)  x  1, so it is of the form f(x)  mx  b, where m

1 2

and b  1.

3. Sample answer: x  y  2

4. No, the variables have an exponent other than 1.

5. yes

6. 3x  y  5; 3, 1, 5

7. 2x  5y  3; 2, 5, 3

8. 2x  3y  3; 2, 3, 3

5 3

9.  , 5

10. 2, 2 y

y

x

O

x

O

y  3x  5

xy20

11. 2, 3

12. 3, y

3 2 y

3x  2y  6 O

x

x

O 4x  8y  12

©Glencoe/McGraw-Hill

25

Algebra 2

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Page 26 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

13. $177.62

14. 563.00 euros

15. yes

16. No; x appears in a denominator.

17. No; y is inside a square root.

18. No; x has exponents other than 1.

19. No; x appears in a denominator.

20. yes

21. No; x has an exponent other than 1.

22. No; x is inside a square root.

23. x 2  5y  0

24. h(x )  x 3  x 2  3x

25. 7200 m

26. Sound travels only 1715 m in 5 seconds in air, so it travels faster underwater.

27. 3x  y  4; 3, 1, 4

28. 12x  y  0; 12, 1, 0

29. x  4y  5; 1, 4, 5

30. x  7y  2; 1, 7, 2

31. 2x  y  5; 2, 1, 5

32. x  2y  3; 1, 2, 3

33. x  y  12; 1, 1, 12

34. x  y  6; 1, 1, 6

35. x  6; 1, 0, 6

36. y  40; 0, 1, 40

37. 25x  2y  9; 25, 2, 9

38. 5x  4y  2; 5, 4, 2

39. 3, 5

40. 6, 2 y

y

2x  6y  12

5x  3y  15

x O

O

©Glencoe/McGraw-Hill

26

x

Algebra 2

Chapter 2

PQ245-6457F-P02[020-055].qxd

41.

10 , 3

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Page 27 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

5 2



42. 5, 2 y

y

3x  4y  10  0

x

O

x

O

2x  5y  10  0

43. 0, 0

44. y

1 , 2

2 y

yx O

x

x

O

y  4x  2

45. none, 2

46. none, 4

y

y y4 x

O

x

O

y  2

48. 1, none

47. 8, none 8 6 4 2 8 64 2 2 4 6 8

©Glencoe/McGraw-Hill

y

y

x1

x8 O 2 4 6

O

x

x

27

Algebra 2

Chapter 2

PQ245-6457F-P02[020-055].qxd

49.

1 , 4

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Page 28 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

1

50. 6, 3 g (x )

f (x ) f (x )  4x  1

g (x )  0.5x  3 O

x

O

51.

y

x

52. Sample answer: x  y  2

x y  5

x O

xy0 x  y  5

The lines are parallel but have different y-intercepts. 53. 90C

54. 4 km

55.

160 120 80 40

56. 1.75b  1.5c  525

T (d )

4 32

O1 2 3 4 d 40 80 120 T (d )  35d  20 160

57.

c 350 300 250 200 150 100 50 0

58. Yes; the graph passes the vertical line test.

1.75b  1.5c  525

100

©Glencoe/McGraw-Hill

200

400b

28

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Page 29 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

21 2

59. no

60.

61. A linear equation can be used to relate the amounts of time that a student spends on each of two subjects if the total amount of time is fixed. Answers should include the following. • x and y must be nonnegative because Lolita cannot spend a negative amount of time studying a subject. • The intercepts represent Lolita spending all of her time on one subject. The x-intercept represents her spending all of her time on math, and the y-intercept represents her spending all of her time on chemistry. 63. B

62. B

units2

64. D  {1, 1, 2, 4}, R  {4, 3, 5}; yes y (1, 5) ( 1, 3)

(4, 3)

x

O (2, 4)

66. 5x 0 1  x  26

65. D  {0, 1, 2}, R  {1, 0, 2, 3}; no y (1, 3) (0, 2) (1, 0) O

©Glencoe/McGraw-Hill

x (2, 1)

29

Algebra 2

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Page 30 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

67. 5x 0 x  6 or x  26

68. $7.95

69. 3s  14

70. 4 1 4

1 3

72. 

73. 2

74. 

75. 5

76.

77. 0.4

78. 0.8

71.

3 2

4 15

Lesson 2-3 Slope Pages 71–74 1. Sample answer: y  1

2. Sometimes; the slope of a vertical line is undefined.

3. Luisa; Mark did not subtract in a consistent manner when using the slope formula. If y2  5 and y1  4, then x2 must be 1 and x1 must be 2, not vice versa.

4. 0

1 2

5.  7.

6. 1

O

©Glencoe/McGraw-Hill

8.

y

x

y

O

30

x

Algebra 2

Chapter 2

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9.

12:22 PM

Page 31 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

10.

y

y

x

O

O

11.

x

12. 5.5/hr

y

O

x

13. 1.25/hr

14. 2:00 P.M.–4:00 P.M.

5 2

15.  17.

16. 13

3 5

18. 4

19. 0

20. 1

21. 8

22. undefined

23. 4

24. 

25. undefined

26. 0

27. 1

28. 9

29. about 0.6

30. about 1.3

31.

32.

5 4

y

y

O

O

©Glencoe/McGraw-Hill

x

x

31

Algebra 2

Chapter 2

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33.

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Page 32 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

34.

y

y

x

O

O

35.

36.

y

x

O

x

y

O

x

37. about 68 million per year

38. about 32 million per year

39. The number of cassette tapes shipped has been decreasing.

40. 55 mph

41. 45 mph

42. speed or velocity

43.

O

45.

x

y

O

46.

y

O

©Glencoe/McGraw-Hill

44.

y

x

y

O

32

x

x

Algebra 2

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Page 33 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

y

47.

O

49.

48.

x

y

O

50.

y

x

y

x O O

51. Yes; slopes show that adjacent sides are perpendicular.

52. 1

53. The grade or steepness of a road can be interpreted mathematically as a slope. Answers should include the following. • Think of the diagram at the beginning of the lesson as being in a coordinate plane. Then the rise is a change in y-coordinates and the horizontal distance is a change in x-coordinates. Thus, the grade is a slope expressed as a percent.

54. D

©Glencoe/McGraw-Hill

33

x

Algebra 2

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12:22 PM

Page 34 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

y

x y  0.08x O

55. D

56. The graphs have the same y-intercept. As the slopes increase, the lines get steeper.

57. The graphs have the same y-intercept. As the slopes become more negative, the lines get steeper.

58. 10, 4 8 2x  5y  20 6 4 2 108 64 2 2 4 6 8

59. 2,

8 3

y

O 2 4x

60. 0, 0 y

y

O

y  7x

x O

4x  3y  8  0

x

61. 7

62. 5

5 2

63. 

64. 3a 4

65. 5x 0 1  x  36

66. 5z 0 z  7356

©Glencoe/McGraw-Hill

34

Algebra 2

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Page 35 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

67. at least 8

68. 17a b

69. 9

70. y  9  x

71. y  4x  2

72. y  3x  7

5 2

73. y  x 

1 2

2 3

75. y   x 

3 5

74. y  x 

4 5

11 3

Chapter 2 Practice Quiz 1 Page 74 1. D  {7, 3, 0, 2}, R  {2, 1, 2, 4, 5}

2. 375

3. 6x  y  4

4. 10, 6 y

3x  5y  30

x O

5.

y O

©Glencoe/McGraw-Hill

x

35

Algebra 2

Chapter 2

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Lesson 2-4

Page 36 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

Writing Linear Equations Pages 78–80

1. Sample answer: y  3x  2

2. 6, 0

3. Solve the equation for y to get 2 3 y  x  . The slope of this

4. 2, 5

5

5

3 . 5

line is The slope of a parallel line is the same. 3 2

6. y  0.5x  1

5.  , 5

5 2

3 4

8. y   x  16

7. y   x  2 3 5

9. y   x 

16 5

10. y  x  2

5 4

11. y  x  7

12. B

2 3

13.  , 4 15.

1 , 2

14.

3 , 4

0 3 5

5 2

16.  , 6



17. undefined, none

18. c, d

19. y  0.8x

20. y   x 

21. y  4

22. y  2

23. y  3x  6

24. y  0.25x  4

1 2

25. y   x 

5 3

3 2

7 2

26. y  x 

4 5

17 5

30. no slope-intercept form for x7 3 2

31. y  0

32. y  x

33. y  x  4

34. y  x 

©Glencoe/McGraw-Hill

17 2

28. y  4x

27. y  0.5x  2 29. y   x 

29 3

3 4

36

1 4

Algebra 2

Chapter 2

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35. y  x 

12:22 PM

Page 37 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-02:

10 3

1 15

37. y   x 

36. y  4x  3 23 5

38. y  x  4

39. y  3x  2

40. y  2x  6

41. d  180c  360

42. 180, 360

43. 540

44. y  75x  6000

45. 10 mi

46. y  x  32

9 5

80 60 40 30

10 20 40

y y  95 x  32 x O 10 20 30

47. 68F

48. 40

49. y  0.35x  1.25

50. $11.75

51. y  2x  4

52. A linear equation can sometimes be used to relate a company’s cost to the number they produce of a product. Answers should include the following. • The y-intercept, 5400, is the cost the company must pay if they produce 0 units, so it is the fixed cost. The slope, 1.37, means that it costs $1.37 to produce each unit. The variable cost is 1.37x. • $6770

53. C x y 55. 5  1

54. A

2

56.

5

57. 2

©Glencoe/McGraw-Hill

5 , 2

5

58. 3

37

Algebra 2

Chapter 2

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59. 0

60. 0.55 s

62. 5x 0 x  66

61.

63. 5r 0 r  66

64. 3

65. 6.5

66. 323.5

67. 5.85

Lesson 2-5 Modeling Real-World Data: Using Scatter Plots Pages 83–86 2. D  {1, 1, 2, 4}, R  {0, 2, 3}; Sample answer using (1, 0) and (2, 2): 4

1. d

3. Sample answer using (4, 130.0) and (6, 140.0): y  5x  110

4a.

Atmospheric Temperature Temperature (˚C)

16 14 12 10 8 6 4 2 0

1000

2000 3000 Altitude (ft)

4000

5000

4b. Sample answer using (2000, 11.0) and (3000, 9.1): y  0.0019x  14.8 4c. Sample answer: 5.3C 5a.

6a.

60 50 40 30 20 10 0 ’88 ’90 ’92 ’94 ’96 ’98 ’00 Year

©Glencoe/McGraw-Hill

Lives Saved by Minimum Drinking Age Lives (thousands)

Households (millions)

Cable Television 80 70

38

25 20 15 10 5 0 ’94 ’95 ’96 ’97 ’98 ’99 ’00 Year

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5b. Sample answer using (1992, 57) and (1998, 67): y  1.67x  3269.64 5c. Sample answer: about 87 million

6b. Sample answer using (1996, 16.5) and (1998, 18.2): y  0.85x  1680.1 6c. Sample answer: 28,400

7a.

8a.

2000–2001 Detroit Red Wings

Bottled Water Consumption 14 12 10 Gallons

Assists

60 50 40 30 20

8 6 4

10 0

2 0

10 20 30 40 Goals

’91

’93

’95 Year

’97

’99

7b. Sample answer using (4, 5) and (32, 37): y  1.14x  0.44 7c. Sample answer: about 13

8b. Sample answer using (1993, 9.4) and (1996, 12.5): y  1.03x  2043.39 8c. Sample answer: about 26.9 gal

9a.

10. Sample answer using (1990, 563) and (1995, 739): y  35.2x  69,485

Revenue ($ millions)

Broadway Play Revenue 700 600 500 400 300 200 100 0

1 2 3 4 Seasons Since ’95–’96

9b. Sample answer using (1, 499) and (3, 588): y  44.5x  454.5, where x is the number of seasons since 1995–1996 9c. Sample answer: about $1078 million or $1.1 billion 11. Sample answer: $1091

©Glencoe/McGraw-Hill

12. The value predicted by the equation is somewhat lower than the one given in the graph. 39

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13. Sample answer: Using the data for August and November, a prediction equation for Company 1 is y  0.86x  25.13, where x is the number of months since August. The negative slope suggests that the value of Company 1’s stock is going down. Using the data for October and November, a prediction equation for Company 2 is y  0.38x  31.3, where x is the number of months since August. The positive slope suggests that the value of Company 2’s stock is going up. Since the value of Company 1’s stock appears to be going down, and the value of Company 2’s stock appears to be going up, Della should buy Company 2.

14. No. Past performance is no guarantee of the future performance of a stock. Other factors that should be considered include the companies’ earnings data and how much debt they have.

15.

16. Sample answer using (213, 26) and (298, 23): y  0.04x  34.52

World Cities Precipitation (in.)

40 35 30 25 20 15 10 5 0

200 400 600 Elevation (ft)

18. Sample answer: The predicted value differs from the actual value by more than 20%, possibly because no line fits the data very well.

17. Sample answer: about 23 in.

©Glencoe/McGraw-Hill

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19. Sample answer using (1975, 62.5) and (1995, 81.7): 96.1%

20. Sample answer: The predicted percent is almost certainly too high. Since the percent cannot exceed 100%, it cannot continue to increase indefinitely at a linear rate.

21. See students’ work.

22. Data can be used to write a linear equation that approximates the number of Calories burned per hour in terms of the speed that a person runs. Answers should include the following. • Calories Burned While Running Calories

1000 800 600 400 200 0

5 6 7 8 Speed (mph)

9

• Sample answer using (5, 508) and (8, 858): y  116.67x  75.35 • about 975 calories; Sample answer: The predicted value differs from the actual value by only about 2%. 23. D

24. A

25. 1988, 1993, 1998; 247, 360.5, 461

26. y  21.4x  42,296.2

27. 354

28. about (1993, 356.17)

29. y  21.4x  42,294.03

30. about 613, about 720

31. y  4x  6

32. y   x 

33. 3

34. 7

©Glencoe/McGraw-Hill

3 7

41

6 7

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29 3

36.

37 3

37. 5x 0 x  7 or x  16

38. 3

39. 11

40. 0

41.

2 3

42. 1.5

Lesson 2-6 Special Functions Pages 92–95 2. 1

1. Sample answer: [[1.9]]  1

3. Sample answer: f(x)  0 x  10

4. A

5. S

6. D  all reals, R  all integers

7. D  all reals, R  all integers

8. D  all reals, R  all nonnegative reals

g (x )

h (x )

g (x )  冀2x 冁

h (x )  |x  4|

O

x O

©Glencoe/McGraw-Hill

42

x

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10. D  all reals, R  5y 0 y 26

9. D  all reals, R  all nonnegative reals

g (x )

x

O

11. D  all reals, R  all reals

12. step function

13.

14. $6

0

Time (hr)

15. C

16. A

17. S

18. S

19. A

20. P

21.

5 4 3 2 1 O

22.

y

60

x 180 300

1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0

1 2 3 4 5 6 7 8 9 Minutes

C

©Glencoe/McGraw-Hill

43

C

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24. D  all reals, R  all integers

23. $1.00

f (x )

x

O

f (x )  冀x  3冁

25. D  all reals, R  all integers

26. D  all reals, R  all even integers

g (x )

f (x )

g (x )  冀x  2冁 x

O

x

O

f (x )  2冀x 冁

27. D  all reals, R  {3a 0 a is an integer.} 12 9 6 O 4 3 2 1 3 6 9 12

28. D  all reals, R  all integers

h (x )

g (x )

h (x )  3冀x 冁 x 1 2 3 4

x

O

g (x )  冀x 冁  3

29. D  all reals, R  all integers

30. D  all reals, R  all nonnegative reals

f (x ) f (x )  冀x 冁  1 O

©Glencoe/McGraw-Hill

x

44

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32. D  all reals, R  {y 0 y  3}

31. D  all reals, R  all nonnegative reals

g (x )

h (x )

h (x )  |x |

g (x )  |x |  3

x

O

x

O

33. D  all reals, R  {y 0 y  4}

34. D  all reals, R  all nonnegative reals

g (x )

h (x ) g (x )  |x |  4 x

O

O

h (x )  |x  3|

x

36. D  all reals, R  all nonnegative reals

35. D  all reals, R  all nonnegative reals

f (x )

f (x )

f (x )  |x  2| x

O

|

f (x )  x  1 4

|

O

x

38. D  all reals, R  {y 0 y  3}

37. D  all reals, R  all nonnegative reals

f (x )

f (x )

O

|

f (x )  x  1 2

©Glencoe/McGraw-Hill

|

O

x

x

45

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39. D  {x 0 x  2 or x  2}, R  {1, 1}

40. D  all reals, R  {y 0 y 0 or y  2} f (x )

h (x )

O

x

x

O

41. D  all reals, R  {y 0 y  2}

42. D  all reals, R  all nonnegative whole numbers

g (x )

f (x ) O

x O

x

f (x )  冀|x |冁

43. D  all reals, R  all nonnegative whole numbers

44.

g (x )

O

2 if x  1 f(x)  • 2x if 1 x 1 x if x  1

x

g (x )  |冀x 冁|

45. f (x)  0x  2 0

46. {x 0 x  0}

47.

48.

©Glencoe/McGraw-Hill

46

f (x)  e

0 if 0 x 300 0.8 (x  300) if x  300

Algebra 2

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50. A step function can be used to model the cost of a letter in terms of its weight. Answers should include the following. • Since the cost of a letter must be one of the values $0.34, $0.55, $0.76, $0.97, and so on, a step function is the best model for the cost of mailing a letter. The gas mileage of a car can be any real number in an interval of real numbers, so it cannot be modeled by a step function. In other words, gas mileage is a continuous function of time. •

y |x |  |y |  3

x

Cost ($)

O

2.10 1.80 1.50 1.20 0.90 0.60 0.30

0

1 2 3 4 5 6 7 Weight (oz)

51. B

52. D

53. Life Expectancy

54. Sample answer using (10, 69.7) and (47, 76.5): y  0.18x  67.9

78 76 74 72 70

Years Since 1950

56. y  3x  10

55. Sample answer: 78.7 yr

©Glencoe/McGraw-Hill

47

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58. {x 0 x  3}

57. y  x  2

1 0 1 2 3 4 5 6

59. e y ` y  f 5 6

60. yes

3 2 1 0 1 2 3

61. no

62. no

63. yes

64. no

65. yes

Chapter 2 Practice Quiz 2 Page 95 2 3

1. y   x 

11 3

2. Houston Comets 250 200 150 100 50 0

65 70 75 80 Height (in.)

4. Sample answer: 168 Ib

3. Sample answer using (66, 138) and (74, 178): y  5x  192 5. D  all reals, R  nonnegative reals f (x )

f (x )  |x  1| O

©Glencoe/McGraw-Hill

x

48

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Lesson 2-7

Graphing Inequalities Pages 98–99

1. y 3x  4

2. Substitute the coordinates of a point not on the boundary into the inequality. If the inequality is satisfied, shade the region containing the point. If the inequality is not satisfied, shade the region that does not contain the point.

3. Sample answer: y  0 x 0

4.

y

y 2 x

O

6.

5.

y

O

x

x y 0

7.

8.

y

y

y  |2x |

x

O

O

x

x  2y  5

©Glencoe/McGraw-Hill

49

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10. 10c  13d 40

y

x O

11.

y  3|x |  1

12. No; (3, 2) is not in the shaded region.

d 10c  13d  40

c O

13.

14.

y

y 3  x  3y

x O

x

O

x  y  5

y

15.

16.

y  6x  2 x

O

17.

18.

y

y

y  4x  3

O

x

O

x

y  2  3x

©Glencoe/McGraw-Hill

50

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20.

y

y

y 1 y 14 x

O

21.

x

O

22.

y

y

4x  5y  10  0

x

O

x

O

x  6y  3  0

23.

24.

y

y

y  1x  5 3

O

y  1x  5

x

2

O

25.

x

26.

y

y

y  |4x | y  |x | O

©Glencoe/McGraw-Hill

x

O

51

x

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28.

y

y y  |x  1|  2

x

O

x

O

y  |x |  3

29.

30.

y

y y  |x |

x y 1 O

x

x

O

x  y  1 y  |x |

31. x  2

32. y  3x  5 y

y x  2

O O

x

x y  3x  5

33.

34. yes

y 350 250 0.4x  0.6y  90

150 50 O

50

150 250 350 x

©Glencoe/McGraw-Hill

52

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35. 4a  3s  2000

36.

800

s

600

4a  3s  2000

400 200

a 200 400 600 800

O

38. 1.2a 1.8b  9000

37. yes

b 6000

1.2a  1.8b  9000

4000 2000 O

a 2000 4000 6000 8000

40.

39. yes

y

|y |  x O

42. A

41. Linear inequalities can be used to track the performance of players in fantasy football leagues. Answers should include the following.

©Glencoe/McGraw-Hill

x

53

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• Let x be the number of receiving yards and let y be the number of touchdowns. The number of points Dana gets from receiving yards is 5x and the number of points he gets from touchdowns is 100y. His total number of points is 5x  100y. He wants at least 1000 points, so the inequality 5x  100y  1000 represents the situation. • y 12

5x  100y  1000

10 8 6 4 2 O 50

100 200

300 x

• the first one 43. B

44.

[10, 10] scl: 1 by [10, 10] scl: 1

45.

46.

[10, 10] scl: 1 by [10, 10] scl: 1

[10, 10] scl: 1 by [10, 10] scl: 1

©Glencoe/McGraw-Hill

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48. D  all reals, R  all integers

47.

f (x )

x

O [10, 10] scl: 1 by [10, 10] scl: 1

f (x )  冀x 冁  4

49. D  all reals, R  {y 0 y  1}

50. D  all reals, R  all nonnegative reals

g (x )

g (x )  |x |  1

h (x )

O

x O

51.

x

52. Sample answer using (4, 6000) and (6, 8000): y  1000x  2000

Sales vs. Experience 10,000 Sales ($)

h (x )  |x  3|

8000 6000 4000 2000 0

1

2

3 4 Years

5

6

7

53. Sample answer: $10,000

54. 8

55. 3

56.

©Glencoe/McGraw-Hill

55

1 2

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Chapter 3 Systems of Equations and Inequalities Lesson 3-1 Solving Systems of Equations by Graphing Pages 112–115 1. Two lines cannot intersect in exactly two points.

2. Sample answer: x  y  4, x  y  2

3. A graph is used to estimate the solution. To determine that the point lies on both lines, you must check that it satisfies both equations.

4.

y (2, 5)

y  x  3

y  2x  9

x

O

5.

6.

y 3x  2y  10

y 4x  2y  22 O

(2, 2) 2x  3y  10

x x

8. inconsistent

7. consistent and independent y

y 2x  4y  8

yx4

x

y6x O

©Glencoe/McGraw-Hill

(4, 3)

6x  9y  3

O

O

x  2y  2

x

56

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10. y  0.08x  3.2, y  0.10x  2.6

9. consistent and dependent y

x

O

x  2y  8 1 xy4 2

11. The cost is $5.60 for both stores to develop 30 prints.

12. You should use Specialty Photos if you are developing less than 30 prints, and you should use The Photo Lab if you are developing more than 30 prints.

13.

14.

y

y x

O

y  3x  1

y  2x  4

15.

y  3x  8

x

O (1, 2)

(0, 8)

16.

y

yx8 y

2x  3y  12 (3, 2)

x  2y  6 (4, 1)

x

O 2x  y  9

17.

y

x

O 2x  y  4

18.

x  2y  11

y

(7, 6)

7x  1  8y (5, 3) 3x  7y  6

O

x

O

x

5x  11  4y

©Glencoe/McGraw-Hill

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y

19.

20.

x

(1.5, 5)

4x  2y  4

(3.5, 0)

2x  3y  7

y

O

x

O

8x  3y  3

2x  3y  7

21.

22.

y

y y  13 x  6

1 x  2y  5 4

(4, 2)

x

O

(9, 3)

2x  y  6

O x 2 x  y  3 3

23.

24.

y 1 xy0 2

y 4 x  15 y  3 3

x

O

x

O (4, 2)

25. inconsistent yx4

(3, 5)

2 x  35 y  5 3

1 x  12 y  2 4

26. consistent and independent

y

y yx3 x

O

x

O

yx4

©Glencoe/McGraw-Hill

y  2x  6

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27. consistent and independent

28. consistent and dependent

y

y 3x  y  3

xy4

x

O

x O 4x  y  9

6x  2y  6

29. inconsistent

30. consistent and dependent y

y yx5

4x  2y  6

x

O

x O

6x  3y  9

2y  2x  8

31. consistent and independent

32. inconsistent

y

y

2y  x 2y  5  x

x

O

x

8y  2x  1

O 6y  7  3x

33. consistent and independent

34. consistent and dependent

y

y 1.6y  0.4x  1

0.8x  1.5y  10

O

1.2x  2.5y  4 O

©Glencoe/McGraw-Hill

x

0.4y  0.1x  0.25

x

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35. inconsistent y  13 x  2

36. consistent and independent

y

y 4 x  y  2 3

O

x

x

O

3y  x  2 2y  4x  3

38. (1, 3), (2, 1), (2, 3)

37. (3, 1)

y y  2x  1

x

O

2y  x  4

39. y  52  0.23x, y  80

4x  y  7

40. (120, 80) 120 Cost ($)

y  80 80

y  52  0.23x

40

0

40

80 120 Miles

160

41. Deluxe Plan

42. Supply, 200,000; demand, 300,000; prices will tend to rise.

43. Supply, 300,000; demand, 200,000; prices will tend to fall.

44. 250,000; $10.00

©Glencoe/McGraw-Hill

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45. y  304x  15,982, y  98.6x 18,976

Population (Thousands)

46. 2015 24,000

y  98.6x  18,976

20,000 16,000

y  304x  15,982

12,000 0

a b a 48b. b a 48c. b

4

d e d e d , e

8 12 16 Years After 1999

c b



f e

c b



f e

47. FL will probably be ranked third by 2020. The graphs intersect in the year 2015, so NY will still have a higher population in 2010, but FL will have a higher population in 2020.

48a.  ,

49. You can use a system of equations to track sales and make predictions about future growth based on past performance and trends in the graphs. Answers should include the following. • The coordinates (6, 54) represent that 6 years after 1999 both the instore sales and online sales will be $54,000. • The in-store sales and the online sales will never be equal and in-store sales will continue to be higher than online sales.

50. A

51. C

52. (3.40, 2.58)

53. (5.56, 12)

54. (4, 3.42)

55. no solution

56. (9, 3.75)

©Glencoe/McGraw-Hill

61

 

Algebra 2

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58.

57. (2.64, 42.43)

y y  5  3x

O

59.

60.

y

x

y

2x  y  4

x

O

O

x

2y  1  x

61. A

62. C

63. S

64. {13, 13}

65. {15, 9}

66. 

67. {2, 3}

68. e5, f

69. {9}

70. 8  2n

71. x 2  6

72. 41a  52

73.

z 3

7 2

74. x  2

1

75. 9y  1

76. 3x  6y

77. 12x  18y  6

78. 15x  10y  10

79. x  4y

Lesson 3-2 Solving Systems of Equations Algebraically Pages 119–122 1. See students’ work; one equation should have a variable with a coefficient of 1. ©Glencoe/McGraw-Hill

2. There are infinitely many solutions.

62

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3. Vincent; Juanita subtracted the two equations incorrectly; y  y 2y, not 0.

4. (4, 8)

5. (1, 3)

6. (4, 1)

7. (5, 2)

8. (9, 7)

9. (6, 20)

10. no solution

11. a3 , 2 b

12. C

13. (9, 5)

14. (2, 7)

15. (3, 2)

16. (6, 8)

17. no solution

18. (1, 1)

19. (4, 3)

20. (1, 8)

21. (2, 0)

22. (3, 1)

23. (10, 1)

24. (7, 9)

25. (4, 3)

26. (6, 5)

27. (8, 3)

28. (7, 1)

29. no solution

30. (5, 8)

31. a ,

32. a , 2b

1 3

1 2

2 3

3 b 2

1 3

33. (6, 11)

34. infinitely many

35. (1.5, 0.5)

36. (2, 4)

37. 8, 6

38. 2, 12

39. x  y  28, 16x  19y  478

40. 18 members rented skis and 10 members rented snowboards.

41. 4 2-bedroom, 2 3-bedroom

42. (5, 2), (4, 4), (2, 8), (1, 10)

43. x  y  30, 700x  200y  15,000

44. 18 printers, 12 monitors

45. 2x  4y  100, y  2x

46. 10 true/false, 20 multiplechoice

47. Yes; they should finish the test within 40 minutes.

48. a  s  40, 11a  4s  335

©Glencoe/McGraw-Hill

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49. 25 min of step aerobics, 15 min of stretching

50. (4, 6)

51. You can use a system of equations to find the monthly fee and rate per minute charged during the months of January and February. Answers should include the following. • The coordinates of the point of intersection are (0.08, 3.5). • Currently, Yolanda is paying a monthly fee of $3.50 and an additional 8¢ per minute. If she graphs y  0.08x  3.5 (to represent what she is paying currently) and y  0.10x  3 (to represent the other long-distance plan) and finds the intersection, she can identify which plan would be better for a person with her level of usage.

52. C

53. A

54. inconsistent y yx2

x

O

yx1

©Glencoe/McGraw-Hill

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56. consistent and independent

55. consistent and dependent

y

y 4y  2x  4 3x  y  1 O

x

O

y  2x  4

y  12 x  1

57.

x

58.

y

y

x

O

x

O

xy3 5y  4x  20

59.

60. 7x  y  4; 7, 1, 4

y

3x  9y  15 O

x

61. x  y  0; 1, 1, 0

62. 3x  5y  2; 3, 5, 2

63. 2x  y  3; 2, 1, 3

64. x  2y  6; 1, 2, 6

65. 3x  2y  21; 3, 2, 21

66. 0.6 ampere

67. yes

68. no

69. no

70. yes

©Glencoe/McGraw-Hill

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Chapter 3 Practice Quiz 1 Page 122 1.

2.

y

y

y  3x  10

(1, 7)

(3, 2) 2x  3y  12

x

O

y  x  6

2x  y  4

x

O

4. (4, 1)

3. (2, 7) 5. Hartsfield, 78 million; O’Hare, 72.5 million

Lesson 3-3

Solving Systems of Inequalities by Graphing Pages 125–127

1. Sample answer: y  x  3, y  x  2

2. true

3a. 4 3b. 2 3c. 1 3d. 3

4.

y

y2 x

O

x4

5.

6.

y

xy2

y  2x  4 O

y

x  1 yx2

©Glencoe/McGraw-Hill

x

O

x

66

x3

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8. (3, 3), (2, 2), (5, 3)

y y  2x  1

x1 O

x

x  2y  3

9. (4, 3), (1, 2), (2, 9), (7, 4)

10.

10 m

b2

Muffins

8

2.5b  3.5m  28

6 4 2

m3 b

0

11. Sample answer: 3 packages of bagels, 4 packages of muffins; 4 packages of bagels, 4 packages of muffins; 3 packages of bagels, 5 packages of muffins

12.

13.

14.

2

4

6 8 Bagels

12

y

y3 x

O

x2

y

y

x

O

10

y2x x

x  1

©Glencoe/McGraw-Hill

O

y  4

yx4

67

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16.

y

y

y2 3x  2y  6

y  2 x

O

x

O 4x  y  2

yx3

17.

18.

y 4x  3y  7

y  12 x  1

x

O

y

2y  x  6

x

O

y  2x  3

19. no solution

20.

y y1

x3 x

O

x  3

21.

y  1

22. no solution

y x2 x  3y  6 O

x

x  4

23.

24. (0, 0), (0, 4), (8, 0)

y 2x  y  4 2x  4y  7 O

x x  3y  2

©Glencoe/McGraw-Hill

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25. (3, 4), (5, 4), (1, 4)

26. (0, 4), (3, 0), (3, 5)

27. (6, 9), (2, 7), (10, 1)

28. (11, 3), (1, 3), (6, 4), a6, 5 b 1 2

30. 16 units2

29. (4, 3), (2, 7), (4, 1), a7 , 2 b 1 3

1 3

31. 64 units2

32. Hours Raking Leaves

16 14 12

8 6 4

0

16

x  y  15

10

2

33. s 111, s 130, h 9, h 12

y

10x  12y  120 2

x

4 6 8 10 12 14 16 Hours Cutting Grass

34. category 4; 13-18 ft

h

Storm Surge (ft)

14

h  12 12

10

s  130

h9

8

s  111 s 0

80

©Glencoe/McGraw-Hill

100 120 140 Wind Speed (mph)

160

69

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35.

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y 14

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36. Sample answer: 2 pumpkin, 8 soda; 4 pumpkin, 6 soda; 8 pumpkin, 4 soda

2x  1.5y  24

12 10

x  2.5y  26

8 6 4 2 0

2

4

6 8 10 12 14 Pumpkin

x

37. 6 pumpkin, 8 soda

38. 42 units2

39. The range for normal blood pressure satisfies four inequalities that can be graphed to find their intersection. Answers should include the following. • Graph the blood pressure as an ordered pair; if the point lies in the shaded region, it is in the normal range. • High systolic pressure is represented by the region to the right of x  140 and high diastolic pressure is represented by the region above y  90.

40. B

41. Sample answer: y 6, y 2, x 5, x 1

42. (3, 8)

43. (6, 5)

44. (8, 5)

45.

46. infinitely many

y

y 2x  y  3

y  2x  1 (2, 3)

O

x O

y   12 x  4

©Glencoe/McGraw-Hill

x

6x  3y  9

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1 2

48. y  x  6

y x  8y  12

(4, 2)

x

O

2x  y  6

49. 5

50. 12

51. 8

52. 27

53. 5

54. 8.25

Lesson 3-4 Linear Programming Pages 132–135 1. sometimes

2. Sample answer: y x, y x  5, y 0

3.

4.

y

y

(1, 4) (5, 2)

(3, 1)

( 53 , 1)

(1, 2) O O

vertices: (3, 1), Q , 1R;

vertices: (1, 2), (1, 4), (5, 2); max: f (5, 2)  4, min: f (1, 4)  10

©Glencoe/McGraw-Hill

x

x

5 3

min: f (3, 1)  17; no maximum

71

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6.

y

y (7, 8.5)

(1, 3)

(2, 6)

(6, 3)

(0, 1) O

(10, 1)

x

x

O (2, 0)

vertices: (0, 1), (1, 3), (6, 3), (10, 1); max: f (10, 1)  31, min: f (0, 1)  1

(7, 5)

vertices: (2, 0), (2, 6), (7, 8.5), (7, 5); max: f(7, 8.5)  81.5, min: f(2, 0)  16 7.

8.

y

y

(2, 4)

(1, 2)

(2, 3)

(4, 1)

x

O

x

O

(3, 1)

(2, 3) (2, 3)

(3, 2)

vertices: (3, 1), (1, 2), (2, 3), (3,2); max: f(3, 2)  5, min: f(1, 2)  3

vertices: (2, 4), (2, 3), (2, 3), (4, 1); max: f(2, 3)  5; min: f (2, 4)  6 9. c 0, l 0, c  3l 56, 4c  2l 104

ᐉ 28

Leather Tote Bags

10.

24 20

(0, 18 23 )

16 (20, 12)

12 8 4 (0, 0) 0

4

(26, 0) 8

12 16 20 24 Canvas Tote Bags

11. (0, 0), (26, 0), (20, 12), a0, 18 b

12. f(c, l)  20c  35l

13. 20 canvas tote bags and 12 leather tote bags

14. $820

2 3

©Glencoe/McGraw-Hill

72

Algebra 2

28 c

Chapter 3

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16.

y

y

(3, 5)

(6, 13)

x

O

(0, 4) (3, 4) (0, 1)

vertices: (0, 4), (3, 5), (3, 4); max: f (3, 4)  7, min: f (3, 5)  2

(6, 1)

x

O

vertices: (0, 1), (6, 1), (6, 13); max: f (6, 13)  19; min: f (0, 1)  1 17.

18.

y

y

(5, 8) (2, 3)

(4, 4)

(2, 1)

(4, 1)

(1, 4)

x

O (1, 2)

(5, 2)

x

O

vertices: (2, 1), (2, 3), (4, 4), (4, 1); max: f (4, 4)  16; min: f (2, 1)  5

vertices: (1, 4), (5, 8), (5, 2), (1, 2); max: f (5, 2)  11, min: f (1, 4)  5 19.

y

y

20.

(3, 5)

12 8

(3, 1)

O

4

x 4

O

(6, 12) (2, 8) (2, 2) 4

8

x

4

vertices: (3, 1), (3, 5); min: f (3, 1)  9; no maximum

©Glencoe/McGraw-Hill

8

(6, 6)

vertices: (2, 2), (2, 8), (6, 12), (6, 6); max: f(6, 12)  30, min: f(6, 6)  24 73

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22.

y

(0, 2) O (0, 0)

y (0, 7) (4, 3)

(2, 1)

x (3, 0) (0, 0) O

vertices: (0, 0), (0, 2), (2, 1), (3, 0); max: f (0, 2)  6; min: f (3, 0)  12 23.

(2, 0) x

vertices: (0, 0), (0, 7), (4, 3), (2, 0); max: f (4, 3)  14; min: f (0, 7)  14 24.

y

y (8, 6) (0, 4)

(3, 0)

x

O

(4, 0)

(0, 3)

vertices: (3, 0), (0, 3); min: f (0, 3)  12; no maximum 25.

vertices: (0, 4), (4, 0), (8, 6); max: f (4, 0)  4; min: f (0, 4)  8 26.

y

(0, 2)

x

O

y

(0, 2)

(4, 3)

(4, 3) (2, 0)

x

O

O

x

( 73 ,  13 ) vertices: (0, 2), (4, 3), (2, 0); max: f (4, 3)  13, min: f (2, 0)  2

vertices: (0, 2), (4, 3), 7 1 a ,  b; max: f (4, 3)  25, 3

3

min: f (0, 2)  6

©Glencoe/McGraw-Hill

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28.

y

y

(2, 5) (2, 2) (3, 0)

(4, 1)

(0, 1)

x

x

O

(0, 0) O

vertices: (0, 0), (0, 1), (2, 2), (4, 1), (5, 0); max: f (5, 0)  15, min: f (0, 1)  5

vertices: (2, 5), (3, 0); min: f (3, 0)  3, no maximum 29.

y

30a. Sample answer: f (x, y)  2x y 30b. Sample answer: f (x, y)  3y  2x 30c. Sample answer: f (x, y)  x  y 30d. Sample answer: f (x, y)  x  3y 30e. Sample answer: f (x, y)  x  2y

(4, 4) (2, 3)

(2, 1) O

(5, 0)

(5, 3) (4, 1)

x

vertices: (2, 1), (2, 3), (4, 1), (4, 4), (5, 3); max: f(4, 1)  0, min: f (4, 4)  12 31. g 0, c 0, 1.5g  2c

85, g  0.5c 40

Graphing Calculators

32.

50

g

40 30 (0, 42.5) 20 10 0

(0, 0)

(30, 20) (40, 0)

10 20 30 40 CAS Calculators

c 50

33. (0, 0), (0, 42.5), (30, 20), (40, 0)

34. f (g, c)  50g  65c

35. 30 graphing calculators, 20 CAS calculators

36. $2800

37. See students’ work.

38. c 0, s 0, c  s 4500, 4c  5s 20,000

©Glencoe/McGraw-Hill

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39. (0, 0), (0, 4000), (2500, 2000), (4000, 0)

40. 2500 acres of corn, 2000 acres soybeans; $125,000

S 4000 3000 2000

(0, 4000)

(2500, 2000)

1000 (0, 0) 0

(4500, 0) 2000

4000

c

41. 4000 acres corn, 0 acres soybeans; $130,500

42. 3 chocolate chip, 9 peanut butter

43. There are many variables in scheduling tasks. Linear programming can help make sure that all the requirements are met. Answers should include the following. • Let x  the number of buoy replacements and let y  the number of buoy repairs. Then, x 0, y 0, x 8 and x  2.5y 24. The captain would want to maximize the number of buoys that a crew could repair and replace, so f (x, y)  x  y. • Graph the inequalities and find the vertices of the intersection of the graphs. The coordinate (0, 24) maximizes the function. So the crew can service the maximum number of buoys if they replace 0 and repair 24 buoys.

44. A

©Glencoe/McGraw-Hill

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46.

45. C

y

2y  x  4

x

O

yx4

47. 

48. (5, 8) y

3x  2y  6

x

O

y  3x  1 2

49. (2, 3) 51. c  average cost each year; 15c  3479  7489 53. Additive Inverse 55. Multiplicative Inverse 57. 9 59. 16 61. 8

50. (5, 1) 52. about $267 per year 54. 56. 58. 60. 62.

Associative Property ( ) Distributive Property 5 3 4

Chapter 3 Practice Quiz 2 Page 135 1.

y

2.

yx0

y yx3

x

O

y  3x  4

yx4

©Glencoe/McGraw-Hill

O

77

x

Algebra 2

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3.

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4.

4x  y  16

y (1, 6) (0, 4)

x  3y  15

(0, 0)

x

O

O

(3, 0)

x

vertices: (0, 0), (0, 4), (1, 6), (3, 0); max: f (1, 6)  8, min: f (0, 0)  0 5.

y (5, 6)

(1, 3) (5, 1)

x

O (1, 3)

vertices: (1, 3), (1, 3), (5, 6), (5, 1); max: f (5, 1)  17, min: f (1, 3)  13

Lesson 3-5 Solving Systems of Equations in Three Variables Pages 142–144 1. You can use elimination or substitution to eliminate one of the variables. Then you can solve two equations in two variables.

2. No; the first two equations do represent the same plane, however they do not intersect the third plane, so there is no solution of this system.

3. Sample answer: x  y  z  4, 2x  y  z  9, x  2y  z  5; 3  5  2  4, 2(3)  5  2  9, 3  2(5)  2  5

4. (6, 3, 4)

©Glencoe/McGraw-Hill

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5. (1, 3, 7)

6. infinitely many

7. (5, 2, 1)

8. no solution 10. 6c  3s  r  42,

9. (4, 0, 8)

1 2

c  s  r  13 , r  2s 1 2

12. (3, 4, 7)

11. 4 lb chicken, 3 lb sausage, 6 lb rice 13. (2, 1, 5)

14. (2, 3, 6)

15. (4, 0, 1)

16. no solution

17. (1, 5, 7)

18. (1, 2, 1)

19. infinitely many

20. a , , b

21. a ,  , b

22. (8, 3, 6)

23. (5, 9, 4)

24. 3, 12, 5

25. 8, 1, 3

26. 1-$100, 3-$50, and 6-$20 checks

27. enchilada, $2.50; taco, $1.95; burrito, $2.65

28. $7.80

29. x  y  z  355, x  2y  3z  646, y  z  27

30. 88 3-point goals, 115 2-point goals, 152 1-point free throws

1 3

1 3 9 2 2 2

1 1 2 4

4 3 4 2 x 3

1 3 1 x 3

31. a  , b  , c  3; y

©Glencoe/McGraw-Hill



32. You can write a system of three equations in three variables to find the number of each type of medal. Answers should include the following. • You can substitute b  6 for g and b  8 for s in the equation g  s  b  97. This equation is now in terms of b. Once you find b, you can substitute again to find g and s. The U.S. Olympians won 39 gold medals, 25 silver medals, and 33 bronze medals.

3

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• Another situation involving three variables is winning times of the first, second, and third place finishers of a race. 33. D

34. A

35. 120 units of notebook paper and 80 units of newsprint

36.

y yx 2

x

O

y  7  2x

37.

38.

y

y

3x  y  3

3x  y  1

O O

x

x

2y  x  4

4y  2x  4

39. Sample answer using (7, 15) and (14, 22): y  x  8

40. Sample answer: about 47¢

41. x  3y

42. 2z  8

43. 9s  4t

44. 18a  16b

©Glencoe/McGraw-Hill

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Chapter 4 Matrices Lesson 4-1 Introduction to Matrices Pages 156–158 2. Sample answers: row matrix, [1 2 3], 1  3;

1. The matrices must have the same dimensions and each element of one matrix must be equal to the corresponding element of the other matrix.

1 2

column matrix, B R, 2  1; 1 2 R, 3 4

square matrix, B

0 0 R, 0 0

zero matrix, B 3. Corresponding elements are elements in the same row and column positions.

4. 1  5

5. 3  4

6. (5, 6)

7. (3, 3)

8.

Fri High Low

B

10. 2  3

11. 3  1

12. 4  3

13. 3  3

14. 2  5

15. 3  2

16. (2.5, 1, 3)

17. a3,  b

18. (5, 3)

19. (3, 5, 6)

20. (2, 5)

21. (4, 3)

22. (1.5, 3)

23. (14, 15)

24. (2, 7)

25. (5, 3, 2)

26. Child Senior

81

Sat Sun Mon Tue

Evening Matinee Twilight Adult

©Glencoe/McGraw-Hill

22

88 88 90 86 85 R 54 54 56 53 52

9. 2  5

1 3

2  2;

7.50 C 4.50 5.50

5.50 4.50 5.50

3.75 3.75 S 3.75

Algebra 2

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27. 3  3

28.

Cost

Catalina Grill Oyster Club Casa di Pasta Mason’s Steakhouse

29. Sample answer: Mason’s Steakhouse; it was given the highest rating possible for service and atmosphere, location was given one of the highest ratings, and it is moderately priced.

30.

31.

32.

Double Suite

Weekend

60 70 75 B R 79 89 95

Atmosphere Location

* ** *** ****

* * *** ****

* ** ¥ *** ***

Weekday Weekend Single

Single Double Suite

Weekday

** ≥ *** **** **

Service

1 2 4 G 7 11 16 22

60 79 C 70 89 S 75 95

3 5 8 12 17 23 30

6 9 13 18 24 31 39

10 14 19 25 32 40 49

15 20 26 33 41 50 60

21 27 34 42W 51 61 72

33. row 6, column 9

34. Matrices are used to organize information so it can be read and compared more easily. Answers should include the following. • If you want the least expensive vehicle, the compact SUV has the best price; the large SUV has the most horsepower, towing capacity and cargo space, and the standard SUV has the best fuel economy. • Sample answer: Matrices are used to report stock prices in the newspaper.

35. B

36. C

37. (7, 5, 4)

38. (7, 3, 9)

©Glencoe/McGraw-Hill

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39. a3, 5, 11b 4 3

40.

y y  2x  15

yx 2

y3

x

O

vertices: (1, 3), (6, 3), a ,

13 19 b; 3 3

max: f a ,

13 19 b 3 3



83 , 3

min: f (1, 3)11 42.

41.

3

 12

y

vertices: (3, 1), a , 15 2

5 b, 2

vertices: (2, 1), (6, 3); min: f(2, 1)  1, no maximum

3 17 a , b; 2 2 . 15 5 max: f a , b  35, 2 2 3 17 min: f a , b  1 2 2

43.

44. step function

Cost ($)

6 5 4 3 2 1 0

1

©Glencoe/McGraw-Hill

2 3 4 Hours

5

83

Algebra 2

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45. $4.50

46. 2

47. 2

48. 0

49. 20

50. 3

51. 10

52. 6.2

53. 18

54. 17

55. 3

56. 75

57.

3 2

Lesson 4-2

Operations with Matrices Pages 163–166

1. They must have the same dimensions.

2. Sample answer: [3 1], [3 1]

4 4 3. C 4 4 S 4 4

4. impossible 18 3 15 6 R 21 9 6 24

1 10 R 7 5

6. B

22 8 R 3 24

8. B

5. B

10 6 R 1 7

7. B

21 29 R 12 22

3 30 R 26 11

9. B

16,763 14,620 11. Males  E14,486 9041 5234 16,439 14,545 Females  E12,679 7931 5450

©Glencoe/McGraw-Hill

10. B 549,499 477,960 455,305U, 321,416 83,411

1,006,372 883,123 12. E 795,785U 579,002 216,646

456,873 405,163 340,480U 257,586 133,235 84

Algebra 2

Chapter 4

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10 14. C 4 S 5

13. No; many schools offer the same sport for males and females, so those schools would be counted twice.

15 0 4 R 0 13 5

15. impossible

16. B

4 8 2 17. C 6 10 16 S 14 12 4

18. [15 29 65 2]

13 19. C 3 S 23

1.8 9.08 20. C 3.18 31.04 S 10.41 56.56 4 15

1.5 3 R 21. B 4.5 9 1

23. C

22. C

52

3

9

2 10 3

2 1 3

1 2 2

3 2

2

S

13 10 7S 24. C 4 7 5

S

2 1 25. C 4 1 S 7 4

0 16 26. C 8 20 S 28 4

38 4 27. C 32 6 S 18 42

12 13 28. C 3 8 S 13 37

2 29. D 1

4

2 3

120 97 64 75 30. Friday: C 80 59 36 60 S, 72 84 29 48

5T

6 1

112 87 56 74 Saturday: C 84 65 39 70 S 88 98 43 60

©Glencoe/McGraw-Hill

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232 184 120 149 31. C 164 124 75 130 S 160 182 72 108

8 10 8 1 6 3 10 S 32. C 4 16 14 14 12

245 228 33. E319U 227 117

15 41 34. E35U 27 51

35. 1996, floods; 1997, floods; 1998, floods; 1999, tornadoes; 2000, lightning

36. Residents: Child Adult Before 6 3.00 4.50 B R After 6 2.00 3.50 Nonresidents: Child Adult Before 6 4.50 6.75 B R After 6 3.00 5.25

1.50 2.25 37. B R 1.00 1.75

38. Before 6:00: Child Adult Residents 3.00 4.50 B R Nonresidents 4.50 6.75 After 6:00: Child Adult Residents 2.00 3.50 B R Nonresidents 3.00 5.25

1.00 1.00 39. B R 1.50 1.50

40. 0.5 0.75 3 1 1.5 6 R B R 2B 2 8 0.2 1 4 0.1 42. D

41. You can use matrices to track dietary requirements and add them to find the total each day or each week. Answers should include the following. 566 18 7 • Breakfast  C 482 12 17 S , 530 10 11

©Glencoe/McGraw-Hill

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785 22 19 Lunch  C 622 23 20 S, 710 26 12 1257 40 26 Dinner  C 987 32 45 S 1380 29 38 • Add the three matrices: 2608 80 52 £ 2091 67 82 § . 2620 65 61 43. A

44. 2  2

45. 1  4

46. 2  4

47. 3  3

48. 3  2

49. 4  3

50. (3, 4, 0)

51. (5, 3, 7)

52. a , 6,  b

53. (2, 5)

54. (3, 1)

55. (6, 1)

56. 0.30p  0.15s  6

57.

58. No, it would cost $6.30.

59. Multiplicative Inverse

60. Associative Prop. ()

61. Distributive Property

62. Commutative Prop. ()

©Glencoe/McGraw-Hill

1 4

87

1 6

Algebra 2

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Lesson 4-3 Multiplying Matrices Pages 171–174 1. Sample answer: 1 2 7 8 C3 4S  B R 9 10 5 6

2. Never; the inner dimensions will never be equal.

3. The Right Distributive Property says that 1A  B2C  AC  BC, but AC  BC  CA  CB since the Commutative Property does not hold for matrix multiplication in most cases.

4. 3  2

5. undefined 15 5 20 7. B R 24 8 32

6. [19 15] 8. not possible

24 R 41

9. B

10. yes A(BC) 2 1 4 1 3 2 B R  ¢B RB R≤ 3 5 8 0 1 2

13 6 2 1 RB R 3 5 24 16

B

50 28 R 81 62 (AB)C

B

2 1 4 1 3 2  ¢B R B R≤ B R 3 5 8 0 1 2

16 2 3 2 RB R 1 2 28 3

B

50 28 R 81 62

B

©Glencoe/McGraw-Hill

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11. [45

55

350 280 65], C 320 165 S 180 120

12. $74,525

13. 4  2

14. 2  2

15. undefined

16. 1  5

17. undefined

18. 3  5 8 11 20. B R 22 12

19. [6]

39 R 18

21. not possible

22. B

1 25 2 R 23. B 29 1 30

24. not possible

24 16 25. C 32 5 S 48 11

0 64 40 26. C 9 11 11 S 3 39 23

27. yes AC  BC 1 2 5 1 B R B R 4 3 2 4

28. yes c (AB) 1 2 5 2 RB R≤ 4 3 4 3

 3¢B

5 2 5 1 R B R 4 3 2 4

 3B

1 9 21 13 RB R 26 8 26 8

B

13 4 R 8 17

B

39 12 R 24 51 A(cB)

B

20 4 R 52 16 (A  B)C

B

 ¢B

1 2 5 R  B 4 3 4

1 2 5 2 R  ¢3 B R≤ 4 3 4 3

B

1 2 15 6 R RB 12 9 4 3

2 5 1 R≤  B R 3 2 4

B

5 1 4 0 R RB 2 4 8 6

B

39 12 R B 24 51

20 4 R 52 16

B

©Glencoe/McGraw-Hill

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29. no C (A  B)

30. no ABC 1 2 5 2 5 1 RB RB R 4 3 4 3 2 4

5 1 1 2 5 2 B R  ¢B RB R≤ 2 4 4 3 4 3

B

5 1 4 0 B RB R 2 4 8 6

B

12 6 R 40 24 AC  BC 1 2 5 1 B RB R 4 3 2 4

B

5 2 5 1 B RB R 4 3 2 4

B

21 13 1 2 RB R 26 8 4 3

B

31 81 R 58 28

13 4 5 1 RB R 8 17 2 4

73 3 R 6 76 CBA

B

5 1 5 2 1 2 RB RB R 2 4 4 3 4 3

B

1 9 21 13 B RB R 26 8 26 8 20 4 R 52 16

B

290 165 210 31. C 175 240 190 S 110 75 0

22 32. C 25 S 18

14,285 33. C 13,270 S 4295

34. $31,850

35. any two matrices B

72 68 36. D 90 86

a b R c d

e f R g h

B

and

where bg  cf, a  d,

49 1.00 63 R T, B 56 0.50 62

and e  h 96.50 99.50 37. D T 118 117 39. $431

38. Juniors

41. $26,360

42. $1460

©Glencoe/McGraw-Hill

40. $24,900

90

Algebra 2

Chapter 4

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43. a  1, b  0, c  0, d  1; the original matrix

44. Sports statistics are often listed in columns and matrices. In this case, you can find the total number of points scored by multiplying the point matrix, which doesn’t change, by the record matrix, which changes for each season. Answers should include the following. • P  R  [479] • Basketball and wrestling use different point values in scoring.

45. B 12 6 47. B R 3 21 20 2 49. B R 28 12

46. A

51. (5, 9)

52. (2, 5, 7)

53. $2.50; $1.50

54.

55. 8; 16

56. 2; 5

©Glencoe/McGraw-Hill

48. impossible 50. (7, 4)

91

3 ; 2

3

Algebra 2

Chapter 4

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57.

58.

59.

60.

Chapter 4 Practice Quiz 1 Page 174 (5, 1) 120 80 64 75 4. B R, 65 105 77 53

1. (6, 3)

2.

3. (1, 3, 5)

112 79 56 74 R 69 95 82 50

B

3 5 R 3 13

232 159 120 149 R 134 200 159 103

6. B

4 3 R 1 3

8. B

5.

B

7.

B

9.

not possible

©Glencoe/McGraw-Hill

10 20 25 R 0 20 35 15 8 10 R 7 23 16

10. B

92

Algebra 2

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Lesson 4-4

1.

Transformation reflection rotation translation dilation

p

Shape same same same changes

p

Size same same same same

Transformations with Matrices Pages 178–181

p

3 3 3 R 2 2 2

2. B

Isometry yes yes yes no

3 3 3 R 1 1 1

4. B

3. Sample answer: 4 4 4 B R 1 1 1 5. A¿(4, 3), B¿(5, 6),

6.

C¿(3, 7)

0 5 5 0 R 4 4 0 0

7. B

8. A¿(0, 12), B¿(15, 12), C¿(15, 0), D¿(0, 0) 10. A¿(0, 4), B¿(5, 4), C¿(5, 0), D¿(0, 0)

9. A¿(0, 4), B¿(5, 4), C¿(5, 0), D¿(0, 0)

4 4 4 R 2 2 2

11. B

12. B

13. D¿(3, 6), E¿(2, 3), F¿(10, 4)

14.

0 1.5 2.5 R 2 1.5 0

16. A¿(0, 6), B¿(4.5, 4.5), C¿(7.5, 0)

15. B

©Glencoe/McGraw-Hill

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Algebra 2

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17.

18. B

19. X¿(1, 1), Y¿(4, 2), Z¿(1, 7)

20.

2 5 4 1 R 4 4 1 1

21. B 23.

22. D¿(4, 2), E¿(4, 5), F¿(1, 4), G¿(1, 1)

y D

G O G'

1 2 7 R 1 4 1

24. E¿(6, 2), F¿(8, 9)

E

F x

D' F' 25.

E' 2 4 2 3 R  (1)  3 3 5 2

26. B

J(5, 3), K(7, 2), L(4, 1)

2 4 2 3 R 3 3 5 2

B

©Glencoe/McGraw-Hill

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Algebra 2

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27.

28. 180 rotation

4 4 4 4 R 4 4 4 4

4 4 4 4 R 4 4 4 4

30. B

29. B

4 4 4 4 R 4 4 4 4

31. B

32. The figures in Exercise 29 and Exercise 30 have the same coordinates, but the figure in Exercise 31 has different coordinates.

33. (1.5, 1.5), (4.5, 1.5), (6, 3.75), (3, 3.75)

34. (3.75, 2.625)

3 35. B R 4

36. (6.5, 6.25)

37. (8, 7), (7, 8), and (8, 7)

38. The object is reflected over the x-axis, then translated 6 units to the right.

39. Multiply the coordinates

40. No; since the translation does not change the y-coordinate, it does not matter whether you do the translation or the reflection over the x-axis first. However, if the translation did change the y-coordinate, then order would be important.

1 0 R, 0 1

by B

then add the

6 0

result to B R.

41. (17, 2), (23, 2)

©Glencoe/McGraw-Hill

42. There is no single matrix to achieve this. However, you could reflect the object over the y-axis and then translate it 2(3) or 6 units to the right.

95

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43. Transformations are used in computer graphics to create special effects. You can simulate the movement of an object, like in space, which you wouldn’t be able to recreate otherwise. Answers should include the following. • A figure with points (a, b), (c, d), (e, f ), (g, h), and (i, j) could be written in a 2  5 a c e g i R b d f h j

matrix B

44. B

and

multiplied on the left by the 2  2 rotation matrix. • The object would get smaller and appear to be moving away from you. 45. A

46. 2  2

47. undefined

48. 2  5

11 24 7 8S 49. C 18 13 33 8 21 51.

20 10 24 50. C 31 46 9 S 10 3 7 52.

D  {all real numbers}, R  {all real numbers}; yes

D  53, 4, 56, R  54, 5, 66; yes

©Glencoe/McGraw-Hill

96

Algebra 2

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54. 0 x 0 4

53.

D  5x 0 x 06, R  5all real numbers6; no

55. 0 x 0 2.8

56. 0 x  1 0 2

57. 0 x  1 0 1

2 3

58. 513 mi

59. 6

60. 5

61. 28

62.

10 3

64.

5 3

63.

9 4

Lesson 4-5 Determinants Pages 185–188 2 1 R 8 4

1. Sample answer: B

2. Khalid; the value of the determinant is the difference of the products of the diagonals.

3. It is not a square matrix.

4. Sample answer: 3 1 4 3 B R, B R 6 5 1 3 2 3 5 6. † 0 1 4 †  9 7 2

5. Cross out the column and row that contains 6. The minor is the remaining 2  2 matrix.

2 `

1 4 0 4 0 1 `  3` `  5` ` 7 2 9 2 9 7

 2(2  28)  3(0  36)  5(0  (9))  2(30)  3(36)  5(9)  60  108  45  213 ©Glencoe/McGraw-Hill

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Algebra 2

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2 3 5 2 3 † 0 1 4 † 0 1 9 7 2 9 7 4 108

0

45 56 0 2 3 5 2 3 † 0 1 4 † 0 1 9 7 2 9 7 4  108  0  (45)  (56)  0  213 7. 38

8. 0 10. 28

9. 40 11. 43

12. 0

13. 45

14. 26 units2

15. 20

16. 22

17. 22

18. 0

19. 29

20. 14

21. 63

22. 6

23. 32

24. 37

25. 32

26. 11.3

27. 58

28. 0

29. 62

30. 60

31. 172

32. 265

33. 22

34. 21

35. 5

36. 49

37. 141

38. 123

39. 6

40.

41. 14.5 units2

42. 12

43. about 26 ft2

44. 2875 mi2

©Glencoe/McGraw-Hill

98

5 , 3

1

Algebra 2

Chapter 4

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1 1 1 45. Sample answer: † 1 1 1 † 1 1 1

46. Multiply each member in the top row by its minor and position sign. In this case the minor is a 3  3 matrix. Evaluate the 3  3 matrix using expansion by minors again.

47. If you know the coordinates of the vertices of a triangle, you can use a determinant to find the area. This is convenient since you don’t need to know any additional information such as the measure of the angles. Answers should include the following. • You could place a coordinate grid over a map of the Bermuda Triangle with one vertex at the origin. By using the scale of the map, you could determine coordinates to represent the other two vertices and use a determinant to estimate the area. • The determinant method is advantageous since you don’t need to physically measure the lengths of each side or the measure of the angles between the vertices.

48. C

49. C

50. 63.25

51. 36.9

52. 25.21

53. 493

54. 0 2 1 2 56. B R 1 2 3

55. 3252 ©Glencoe/McGraw-Hill

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Algebra 2

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57. A¿(5, 2.5), B¿(2.5, 5), C¿(5, 7.5)

58.

2 26 R 9 12 62. undefined 7 69 64. B R 5 16 66. y  x  2 60. B

59. [4] 61. undefined 8]

63. [14

65. 138,435 ft 4 3

67. y   x

68. y  2x  1

1 2

69. y  x  5

70. (0, 3)

71. (1, 9)

72. (2, 1)

73. (1, 1)

74. (2, 5)

75. (4, 7)

Lesson 4-6 Cramer’s Rule Pages 192–194 1. The determinant of the coefficient matrix cannot be zero.

2. Sample answer: 2x  y  5 and 6x  3y  8

3. 3x  5y  6, 4x  2y  30

4. (5, 1)

5. (0.75, 0.5)

6. (6, 8)

7. no solution

8. a5, ,  b 2 3

9. a6,  , 2b 1 2

©Glencoe/McGraw-Hill

1 2

10. s  d  4000, 0.065s  0.08d  297.50

100

Algebra 2

Chapter 4

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11. savings account, $1500; certificate of deposit, $2500

12. (2, 1)

13. (12, 4)

14. (3, 5)

15. (6, 3)

16. (2.3, 1.4)

17. (0.75, 3)

18. (0.75, 0.625)

19. (8.5625, 19.0625)

20. a , 1b

21. (4, 8)

22. (3, 10)

23. a , b

24. (1.5, 2)

25. (3, 4)

26. (1, 3, 4)

27. (2, 1, 3)

28. a ,

2 3

2 5 3 6

29. a

141 , 29

11 39 , 19 19

102 244 b , 29 29



 b 14 19

30. (11, 17, 14)

31. a

32. r  s  8, 7r  5s  50

33. race car, 5 plays; snowboard, 3 plays

34. 8s  13c  604.79,

35. silk, $34.99; cotton, $24.99

36. p  r  c  5, 2r  p  0, 3.2p  2.4r  4c  16.8

37. peanuts, 2 lb; raisins, 1 lb; pretzels, 2 lb

38. If the determinant is zero, there is no unique solution to the system. There is either no solution or there are infinitely many solutions. Sample answer: 2x  y  4 and 4x  2y  8 has a det  0; there are infinitely many solutions of this system. 2x  y  4 and 4x  2y  10 has a det  0; there are no solutions of this system.

155 143 673 b , , 28 70 140

©Glencoe/McGraw-Hill

1 2

5 s  14c  542.30

101

Algebra 2

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39. Cramer’s Rule is a formula for the variables x and y where (x, y) is a solution for a system of equations. Answers should include the following. • Cramer’s Rule uses determinants composed of the coefficients and constants in a system of linear equations to solve the system. • Cramer’s Rule is convenient when coefficients are large or involve fractions or decimals. Finding the value of the determinant is sometimes easier than trying to find a greatest common factor if you are solving by using elimination or substituting complicated numbers.

40. B

41. 111, 69

42. 16

43. 40

44. 53

1 1 1 R 3 3 3

45. B

46. A¿(1, 5), B¿(2, 2), C¿(1, 1)

47.

48.

y y  3x  5 (2, 1)

O

x

y  2x  5

(2, 1)

©Glencoe/McGraw-Hill

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Algebra 2

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49.

50.

y

y 2x  4y  12

xy 7

x

O (4, 3)

x  2y  10

x O

1 x  y  1 2

(4, 3)

no solution

51. c  10h  35 72 9 53. B R 66 23

52. [4 32] 21 54. B R 43

Chapter 4 Practice Quiz 2 Page 194 1 4 1 2 R 2 1 4 1

1. B

2. A¿(1, 2), B¿(4, 1), C¿(1, 4), D¿(2, 1)

3.

4. 22

5. 58

6. 105

7. 26

8. (1, 2)

9. (4, 5)

©Glencoe/McGraw-Hill

10. (1, 2, 1)

103

Algebra 2

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Lesson 4-7 1 0 1. D 0 0

0 1 0 0

0 0 1 0

Identity and Inverse Matrices Pages 198–201

0 0 T 0 1

2. Exchange the values for a and d in the first diagonal in the matrix. Multiply the values for b and c by 1 in the second diagonal in the matrix. Find the determinant of the original matrix. Multiply the negative reciprocal of the determinant by the matrix with the above mentioned changes. 3 3 R 3 3

3. Sample answer: B

4. no

5. yes

6. B

7. no inverse exists

8. 

2 5 R 3 8 4 1 B 27 7

10. yes

9. See students’ work. 11. yes

12. no

13. no

14. yes

15. yes

16. true

17. true

18. true 1 1 0 R 20. B 5 0 5

19. false

1 3

21. no inverse exists 23.

1 1 B 7 4

25.

1 6 B 4 2

22.  B

1 R 3

1 2 R 2 1

24. no inverse exists

7 R 3

©Glencoe/McGraw-Hill

1 R 5

26.

104

7 1 B 34 2

3 R 4

Algebra 2

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6 1 B 12 5

27. 

29.

0 R 2

1 1 B 32 6

5 R 2

3 4



31. 10 C

1  5

5 8

3 10

28. no inverse exists

30. 4 C

S

1 4

3 4

1  6

1 2

S

32a. no 32b. Sample answer: y

C A B x

O A'

A''

B'' C''

34. B

33a. yes 33b. Sample answer:

0 4 4 8 R 0 4 12 8

35. B

37. dilation by a scale factor of

B' C'

0 2 2 4 R 0 2 6 4

36. dilation by a scale factor of 2

1 2

1

38. B D

1 2

0

0

1 2

T;

the graph of the

inverse transformation is the original figure.

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39. MEET_IN_THE_LIBRARY

40. AT_SIX_THIRTY

41. BRING_YOUR_BOOK

42. See students’ work.

43. a  1, d  1, b  c  0

44. A matrix can be used to code a message. The key to the message is the inverse of the matrix. Answers should include the following. • The inverse matrix undoes the work of the matrix. So if you multiply a numeric message by a matrix it changes the message. When you multiply the changed message by the inverse matrix, the result is the original numeric message. • You must consider the dimensions of the coding matrix so that you can write the numeric message in a matrix with dimensions that can be multiplied by the coding matrix. 46. D

45. A 5 9 R 47. B 6 11 3 5



1 5

1 5

2  5

49. C

48. no inverse exists

S

1

1

1 3

1 3

2 3

0V

51. F 

7 3

8 3



1 3 2 5 16

1 2 2 1  8

1 4

0

5 32

3 16

52. F

1 3



53. (2, 4)

©Glencoe/McGraw-Hill

2 5

50. C

3 5

S 1 16



1 V 4 1 32



54. (0, 7)

106

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55. (5, 4, 1)

56. 52

57. 14

58. 0

59. 1

60. 3

61. 5

62.

63.

1 3 3 8

5 2

64. 

65. 7.82 tons/in2

66. 27 1 2

1 2

67. 5

68. 

69. 3

70. 296

71. 300

72. 1

73. 2

74. 6

75. 4

76. 27

77. 34

Lesson 4-8

Using Matrices to Solve Systems of Equations Pages 205–207

1. 2r  3s  4, r  4s  2

2. Sample answer: x  3y  8 and 2x  6y  16

3. Tommy; a 2  1 matrix cannot be multiplied by a 2  2 matrix.

4. B

1 1 x 3 RB RB R 1 3 y 5

3 5 2 a 6. C 4 7 1S  CbS 2 0 1 c

2 3 g 8 RB RB R 5. B 4 7 h 5

7. (5, 2)

9  C 3S 12 8. (1.5, 4)

9. (3, 5)

10. (1, 1.75)

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3 1 x 0 RB RB R 1 2 y 21

11. h  1, c  12

12. B

5 6 a 47 RB RB R 3 2 b 17

4 7 x 2 RB RB R 3 5 y 9

13. B

14. B

3 7 m 43 RB RB R 15. B 6 5 n 10

2 3 5 a 16. C 7 0 3S  CbS 3 6 1 c 1  C 7S 5

3 5 2 x 17. C 1 7 3 S  C y S 4 0 3 z

1 1 0 x 18. C 2 5 6 S  C y S 9 10 1 z

9  C 11 S 1

8  C 27 S 54

3 5 6 r 19. C 11 12 16 S  C s S 5 8 3 t

20. (5, 2)

21  C 15 S 7 21. (3, 4)

22. (2, 3)

23. (6, 1)

24. a , 3b

25. a , 4b

26. (2, 3)

27. (2, 2)

28. (7, 3)

29. (0, 9)

30. a1, b

1 2

1 3

9 2

31. a , b 3 1 2 3

32. 27 h of flight instruction and 23 h in the simulator 34. 80 mL of the 60% solution, and 120 mL of the 40% solution

33. 2010

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35. The solution set is the empty set or infinite solutions.

36. The food and territory that two species of birds require form a system of equations. Any independent system of equations can be solved using a matrix equation. Answers should include the following. • Let a represent the number of nesting pairs of Species A and let b represent the number of nesting pairs of Species B. Then, 140a  120b  20,000 and 500a  400b  69,000. a • B R b 400 1 B 4000 500



120 20,000 RB R; 140 69,000

a  70 and b  85, so the area can support 70 pairs of Species A and 85 pairs of Species B. 37. D

38. 17 small, 24 medium, 11 large

39. (6, 2, 5)

40. (1, 3, 2) 1

1  2

1

42. C

3 4

41. (0, 1, 3) 4 5 R 7 9 45. (4, 2) 43. B

S

44. no inverse exists 46. (4.27, 5.11)

47. (6, 8)

48. about 114.3 ft

49. {4, 10}

50. {5, 1}

51. {2, 7}

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Chapter 5 Polynomials Lesson 5-1 Monomials Pages 226–228 1. Sample answer: (2x 2)3  8x 6 since (2x 2)3  2x 2  2x 2  2x 2  2x  x  2x  x  2x  x  8x 6

2. Sometimes; in general, x y  x z  x yz, so x y  x z  x yz when y  z  yz, such as when y  2 and z  2.

3. Alejandra; when Kyle used the Power of a Product Property in his first step, he forgot to put an exponent of 2 on a. Also, in his second step,

4. x 10

1 4

(2)2 should be , not 4. 5. 16b 4

6. 1

7. 6y 2

8. 

ab 4 9

9. 9p 2q 3

10.

1 w z

9 c d

12.

1 4x 6

11.

2 2

12 6

13. 4.21  105

14. 8.62  104

15. 3.762  103

16. 5  100

17. about 1.28 s

18. a 8

19. b 4

20. n16

21. z10

22. 16x 4

23. 8c 3

24. an

25. y 3z 2

26.

27. 21b5c 3

28. ab

29. 24r 7s 5

30. 24x 4y 4

31. 90a4b4

32. 

©Glencoe/McGraw-Hill

28x 4 y2

1 4y 4

110

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a 2c 2 3b 4 m 4n 9 3

35. 

34.

cd 4 5

36.

a4 16b 4

37.

8y 3 x6

38.

1 x y

39.

1 3 6 v w

40.

a 4b 2 2

41.

2x 3y 2 5z 7

42. 6

2 2

43. 7

44. 4.623  102

45. 4.32  104

46. 1.843  104

47. 6.81  103

48. 5.0202  108

49. 6.754  108

50. 1.245  1010

51. 6.02  105

52. 4.5  102

53. 6.2  1010

54. 4.225  109

55. 1.681  107

56. 6.08  109

57. 2  107 m

58. 1.67  1025

59. about 330,000 times

60. 10010  (102)10 or 1020, and 10100  1020, so 10100  10010.

61. Definition of an exponent

62. (ab)m m factors 6447448  ab  ab  p  ab m factors m factors 64748 64748 aapabbpb  a mb m

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63. Economics often involves large amounts of money. Answers should include the following. • The national debt in 2000 was five trillion, six hundred seventy-four billion, two hundred million or 5.6742  1012 dollars. The population was two hundred eighty-one million or 2.81  108. • Divide the national debt by the population. 5.6742  1012 2.81  108

64. D



$2.0193  104 or about $20,193 per person. 66. (1, 2) 2 5 68. c d 1 2

65. B 67. (3, 3) 69. C

1 2



3 2 S

70. 6

1 2

71. 7

72. (2, 3, 1)

73. (2, 0, 4)

74.

Median Age (yr)

Median Age of Vehicles y 8 7 6 5 4 0 0

10 20 30 Years Since 1970

75. Sample answer using (0, 4.9) and (28, 8.3): y  0.12x  4.9

76. Sample answer: 9.7 yr

77. 7

78. 3

79. 2x  2y

80. 3x  3z

©Glencoe/McGraw-Hill

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81. 4x  8

82. 6x  10

83. 5x  10y

84. 3y  15

Lesson 5-2 Polynomials Page 231–232 1. Sample answer: x 5  x 4  x 3 x

3. x

x

x 2

x

2. 4

x 2

x

4. yes, 1 2

x

x

x

x

x

x

2

5. yes, 3

6. no

7. 10a  2b

8. 3x 2  7x  8 10. 10p 3q 2  6p 5q 3  8p3q 5

9. 6xy  18x 11. y 2  3y  70

12. x 2  9x  18

13. 4z 2  1

14. 4m 2  12mn  9n 2

15. 7.5x 2  12.5x ft 2

16. yes, 2

17. yes, 3

18. no

19. no

20. yes, 6

21. yes, 7

22. 4x 2  3x  7

23. 3y  3y 2

24. r 2  r  6

25. 10m 2  5m  15

26. 4x 2  3xy  6y 2

27. 7x 2  8xy  4y 2

28. 4b 2c  4bdz

29. 12a 3  4ab

30. 15a3b3  30a4b3  15a5b6

31. 6x 2y 4  8x 2y 2  4xy 5

32. 6x 3  9x 2y  12x 3y 2

33. 2a4  3a3b  4a4b4

34. 46.75  0.018x

35. 0.001x 2  5x  500

36. $5327.50

37. p 2  2p  24

38. a 2  9a  18

39. b 2  25

40. 36  z 2

41. 6x 2  34x  48

42. 8y 2  16y  42

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43. a 6  b 2

44. 2m 4  7m 2  15

45. x 2  6xy  9y 2

46. 1  8c  16c 2

47. d 2  2 

1 d4

48. xy 3  y 

1 x

49. 27b 3  27b 2c  9bc 2  c 3

50. x 3  y 3

51. 9c 2  12cd  7d 2

52. 18x 2  27x  10

53. R 2  2RW  W 2

54. 14; Sample answer: (x 8  1)(x 6  1)  x 14  x 8  x 6  1

55. The expression for how much an amount of money will grow to is a polynomial in terms of the interest rate. Answers should include the following. • If an amount A grows by r percent for n years, the amount will be A(1  r )n after n years. When this expression is expanded, a polynomial results. • 13,872(1  r )3, 13,872r 3  41,616r 2  41,616r  13,872 • Evaluate one of the expressions when r  0.04. For example, 13,872(1  r)3  13,872(1.04)3 or $15,604.11 to the nearest cent. The value given in the table is $15,604 rounded to the nearest dollar.

56. D

57. B

58. 64d 6

59. 20r 3t 4

60.

61.

b2 4a 2

©Glencoe/McGraw-Hill

xz 2 y2

62. (1, 4)

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63.

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64.

y

y

x  y  2 x

O

x

O

y   13 x  2

65.

66. x 2

y

2x  y  1

x

O

68. xy 2

67. 2y 3 69. 3a 2

Lesson 5-3 Dividing Polynomials Pages 236–238 1. Sample answer: (x 2  x  5)  (x  1)

2. The divisor contains an x 2 term.

3. Jorge; Shelly is subtracting in the columns instead of adding.

4. 6y  3  2x

5. 5b  4  7a

6. x  12

7. 3a3  9a2  7a  6

8. z 4  2z 3  4z 2  5z  10

9. x 2  xy  y 2

10. x 2  11x  34 

11. b3  b  1

12. 2y  5

13. 3b  5

14. B

15. 3ab  6b 2

16. 5y 

17. 2c 2  3d  4d 2

18. 4n 2  3mn  5m

©Glencoe/McGraw-Hill

115

6y 2 x

60 x2

 3xy 2

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2 b

19. 2y 2  4yz  8y 3z 4

20. a2b  a 

21. b 2  10b

22. x  15

23. n 2  2n  3

24. 2c 2  c  5 

25. x 3  5x 2  11x  22 

39 x2

26. 6w 4  12w 3  24w 2  30w  60

27. x 2

28. x 2  3x  9

29. y 2  y  1

30. m 2  7

31. a3  6a 2  7a  7 

3 a1

32. 2m 3  m 2  3m  1

5 m3

34. 3c 4  c 3  2c 2  4c 

33. x 4  3x 3  2x 2  6x  19 

6 c2

56 x3

9

13 c2 4 b1

35. g  5

36. 2b 2  b  1 

37. t 4  2t 3  4t 2  5t  10

38. y 4  2y 3  4y 2  8y  16

39. 3t 2  2t  3

40. h 2  4h  17 

41. 3d 2  2d  3  43. x 3  x 

2 3d  2

42. x 2  x  1

6 2x  3

44. 2x 3  x 2  1  46. x 2  1 

47. x  2

48. x  3

49. x 2  x  3

50. 2y 2  3y  1

116

2 3x  1

3x  7 x2  2

45. x  3

©Glencoe/McGraw-Hill

51 2h  3

Algebra 2

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51. $0.03x  4 

Page 117 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-05:

1000 x

52. Let x be the number. Multiplying by 3 results in 3x. The sum of the number, 8, and the result of the multiplication is x  8  3x or 4x  8. Dividing by the sum of the number and 2 gives

4x  8 x2

or 4. The end

result is always 4. 53. 170 

170 t 1

54. 85 people

2

55. x 3  x 2  6x  24 ft

56. x  2 s

57. x 2  3x  12 ft /s

58. Sample answer: r 3  9r 2  27r  28 and r  3

59. Division of polynomials can be used to solve for unknown quantities in geometric formulas that apply to manufacturing situations. Answers should include the following. • 8x in. by 4x  s in. • The area of a rectangle is equal to the length times the width. That is, A  /w . • Substitute 32x 2  x for A, 8x for /, and 4x  s for w. Solving for s involves dividing 32x 2  x by 8x. A  /w 2 32x  x  8x (4x  s)

60. A

32x 2  x 8x 1 4x  8 1 8

 4x  s  4x  s s

The seam is

1 8

inch. 62. x 2  4x  14

61. D

©Glencoe/McGraw-Hill

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63. y 4z 4  y 3z 3  3y 2z

64. y 2  2y  15

65. a 2  2ab  b 2

66. 5  102 s or 8 min 20 s

67. y  x  2

68. y  x 

69. 9

70. 12

71. 4

72. 3

73. 6

74. 5

2 3

4 3

Chapter 5 Practice Quiz 1 Page 238 1. 6.53  108

2. 7.2  103

3. 108x 8y 3

4.

5.

x2 z6

a3 b4c 3

6. 2x  5y

7. 3t 2  2t  8 9. m 2  3 

8. n3  n 2  5n  2

19 m4

10. d 2  d  3

Lesson 5-4 Factoring Polynomials Pages 242–244 1. Sample answer: x 2  2x  1

2. Sample answer: If a  1 and b  1, then a 2  b 2  2 but 1a  b2 2  4.

3. sometimes

4. 6x(2x  1)

5. a(a  5  b)

6. (x  7)(3  y)

7. (y  2)(y  4)

8. (z  6)(z  2)

9. 3(b  4)(b  4)

10. (4w  13)(4w  13)

11. (h  20)(h 2  20h  400)

©Glencoe/McGraw-Hill

12.

118

x4 x7

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2y y4

14. x  y cm

15. 2x(y 3  5)

16. 6ab 2(a  3b)

17. 2cd 2(6d  4c  5c 4d )

18. prime

19. (2z  3)(4y  3)

20. (3a  1)(x  5)

21. (x  1)(x  6)

22. (y  1)(y  4)

23. (2a  1)(a  1)

24. (2b  1)(b  7)

25. (2c  3)(3c  2)

26. (3m  2)(4m  3)

27. 3(n  8)(n  1)

28. 3(z  3)(z  5)

29. (x  6)2

30. (x  3)2

31. prime

32. 3(m  n)(m  n)

33. (y 2  z)(y 2  z)

34. 3(x  3y)(x  3y)

35. (z  5)(z 2  5z  25)

36. (t  2)(t 2  2t  4)

37. (p 2  1)(p  1)(p  1)

38. (x 2  9)(x  3)(x  3)

39. (7a  2b)(c  d )(c  d )

40. (8x  3)(x  y  z)

41. (a  b)(5ax  4by  3cz)

42. (a  3b)(3a  5)(a  1)

43. (3x  2)(x  1)

44. (2y  1)(y  4)

45. 30 ft by 40 ft

46.

x1 x4 x5 x2

47.

x5 x6

48.

49.

x4 x  2x  4

50. x

2

51. x  2

52. x  1 s

53. 16x  16 ft /s

54. x  8 cm

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55. (8pn  1)2

56. Factoring can be used to find possible dimensions of a geometric figure, given the area. Answers should include the following. • Since the area of the rectangle is the product of its length and its width, the length and width are factors of the area. One set of possible dimensions is 4x  2 by x  3. • The complete factorization of the area is 2(2x  1) (x  3), so the factor of 2 could be placed with either 2x  1 or x  3 when assigning the dimensions.

57. B

58. C

59. yes

60. no; (x  2)(x 2  2x  4)

61. no; (2x  1)(x  3)

62. yes

63. t 2  2t  1

64. y  3

65. x 2  2

66. x 3  x 2  2x  2 

67. 4x 2  3xy  3y 2

68. 14x 2  26x  4

69. [2]

70. c

71. 15 in. by 28 in.

72. yes

73. no

74. Distributive Property

75. Associative Property ()

76. rational

77. irrational

78. rational

79. rational

80. irrational

1 3x  2

36 7 d 18 4

81. rational

©Glencoe/McGraw-Hill

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Lesson 5-5 Roots of Real Numbers Pages 247–249 1. Sample answer: 64

2. If all of the powers in the result of an even root have even exponents, the result is nonnegative without taking absolute value.

3. Sometimes; it is true when x  0.

4. 8.775

5. 2.668

6. 2.632

7. 4

8. 2

9. 3

10. not a real number

11. x

12. 0 y 0

15. about 3.01 mi

16. 11.358

17. 12.124

18. 0.933

19. 2.066

20. 3.893

21. 7.830

22. 4.953

23. 3.890

24. 4.004

25. 4.647

26. 26.889

27. 59.161

28. 15

29. 13

30. not a real number

31. 18

32. 3

33. 2

34.

14. 0 4x  3y 0

13. 6 0 a 0 b 2

1 4

1 5

36. 0.5

37. 0.4

38. z 2

35.

39.  0 x 0

40. 7 0 m3 0

41. 8a 4

42. 3r

43. c 2

44. 25g 2

46. 5x 2 0 y 3 0

45. 4z 2

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48. 13x 4y 2

47. 6x 2z 2

49. 3p 6 0 q 3 0

50. 2ab

52. 0 4x  y 0

51. 3c 3d 4

54.  0 x  2 0

53. p  q

56. 0 2a  1 0

55. 0 z  4 0 57. not a real number

58. 2

59. 5

60. about 127.28 ft

61. about 1.35 m

62. about 11,200 m s

63. x  0 and y 0, or y  0 and x 0

64. The speed and length of a wave are related by an expression containing a square root. Answers should include the following. • about 1.90 knots, about 3.00 knots, and 4.24 knots • As the value of / increases, the value of s increases.

65. B

66. D

67. 7xy 2(y  2xy 3  4x 2)

68. (a  3)(b  5)

69. (2x  5)(x  5)

70. (c  6)(c 2  6c  36)

71. 4x 2  x  5  73. c

8 x2

72. x 3  x 2  x

810 2320 d 1418 2504

74. (2, 2)

75. (1, 3)

76. (9, 4)

77. x 2  11x  24

78. y 2  3y  10

79. a 2  7a  18

80. a 2  3ab  2b 2

81. x 2  9y 2

82. 6w 2  7wz  5z 2

©Glencoe/McGraw-Hill

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Lesson 5-6 Radical Expressions Pages 254–256 1. Sometimes;

1 n

1a

n

 1a only

2. Sample answer: 22  23  22

when a  1. 3. The product of two conjugates yields a difference of two squares. Each square produces a rational number and the difference of two rational numbers is a rational number.

4. 1527

4 5. 2x 0 y 0 2x

6.

7. 24235

8. 225

214y 4y 3

4 10. 523  323

9. 2a 2b 2 23 3 11. 22 22

12. 3  323  25  215

13. 2  25

14. about 49 mph

15. 923

16. 622

3 17. 322

4 18. 226

19. 5x 2 22

3 20. 2y22

21. 3 0 x 0 y 22y

22. 2ab 2 210a

3

3 24. 4mn23mn 2

4 02 c

26.

1 wz 2

23. 6y 2z 27 25.

1 c 0d 3

27.

26 2

28.

2 54 3

29.

a 2 2b b2

30.

2r 4 2t t5

4

3

32. 60230

31. 36 27 33.

5 2 wz 2

26 2

34.

210 5

35. 323

36. 522

37. 723  222

38. 425  23 26

©Glencoe/McGraw-Hill

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39. 25  522  526  223

40. 6  326  227  242

41. 13  2222

42. 8  2215

43.

28  7 23 13

44.

5 26  3 22 22

45.

1  23 2

46.

12  7 22 23

47.

2x 2  1 x1

48. 2x  1

49. 6  1622 yd, 24  622 yd2

50. The square root of a difference is not the difference of the square roots.

51. 0 ft /s

52. d  v

53. about 18.18 m

54. 80 ft /s or about 55 mph

55. x and y are nonnegative.

56. The formula for the time it takes an object to fall a certain distance can be written in various forms involving radicals. Answers should include the following. • By the Quotient Property

24.9h 4.9

of Radicals, t  Multiply by

2g 2g

22d 2g

.

to

rationalize the denominator. The result is h 

22dg . g

• about 1.12 s 57. B

58. D

59. 12z 4

60. 6ab 3

61. 0 y  2 0

62.

63.

2 4 64. £ 9 15 § 3 5

x1 x4

©Glencoe/McGraw-Hill

x7 x4

124

Algebra 2

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65. c

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1 4 d 5 4

66. 16, 15

67. consistent and independent

68. $4.20

69. 5

70. 2

71. 2, 4

72.  , 1

73. 5x 0 x  66

74. 5x 0 x 76

7 3

75.

1 4

76.

1 2

77.

5 6

78.

13 12

79.

13 24

80.

19 30

81.

3 8

82. 

5 12

Chapter 5 Practice Quiz 2 Page 256 1. x 2y (3x  y  1)

2. prime

3. a(x  3)2

4. 8(r  2s 2)(r 2  2rs 2  4s 4) 6. 4a 2b 3

5. 6 0 x 0 0 y 3 0

7. 0 2n  3 0

8.

9. 1 17

10.

©Glencoe/McGraw-Hill

125

x 2 2y y2 8  3 22 2

Algebra 2

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Lesson 5-7 Rational Exponents Pages 260–262 2. In radical form, the expression would be 216, which is not a real number because the index is even and the radicand is negative.

1. Sample answer: 64

n

3. In exponential1 form 2bm is equal to (b m)n . By the Power of a 1Power Property, m m m n n (b )  b . But, b n is also 1 equal to (b n )mby the Power of a Power Property. This last n expression is equal to ( 2b)m . n n Thus, 2bm  (2b)m.

3 4. 27

3 3 5. 2x 2 or (2x)2

6. 264

1

5

1

7

8. 5

7. 63x 3y 3 9.

1 3

10. 9 11

12. a12

11. 2

2

13. x

2 3

14.

z3 2z

16.

m 3 n3 mn

1

2

3 2

15. a b

2 3

1

17.

z (x  2y)2 x  2y

18. 23x

19. 23

20. $5.11

5 21. 26

3 22. 24

5 5 23. 2c 2 or (2c)2

3 24. x 2 2x 2 1

1

26. 623

25. 232

1

1

2

1

27. 2 z 2

28. 53 x 3 y 3

29. 2

30. 6

31.

1 5

©Glencoe/McGraw-Hill

32.

126

1 27

Algebra 2

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33.

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1 8

1 9

34. 

35. 81

36. 4096

37.

2 3

38. 27

39.

4 3

40.

42. x 3

41. y 4 1

1

43. b 5

44. a9 5 x6 46. x

1

45.

1 2

w5 w

1

1

48. r 2

47. t 4

15

5

49.

a12 6a

51.

y 2  2y 2 y4

50.

2c 16 c

52.

x  3x 2  2 x1

1

3

53. 25

54. 23

6 55. 17 217

6 56. 5255 3

4

57. 25x 2y 2 59.

58. b29a 2b 3

xy 1z z

60.

ab 2 c 2 c 3

61. 12

62. 26

63. 216  5

64. x  x 3z 3

3

1

2

1

1

65. 22  32

66. 2  3 3

67. 880 vibrations per second

68. about 262 vibrations per second

©Glencoe/McGraw-Hill

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69. about 336

70. Rewrite the equation so that the bases are the same on each side. 1 9x  3x 2 1 (32 )x  3x 2 1 32x  3x 2 Since the bases are the same and this is an equation, the exponents must be equal. 1 2

Solve 2x  x  . The result 1 2

is x  . 71. The equation that determines the size of the region around a planet where the planet’s gravity is stronger than the Sun’s can be written in terms of a fractional exponent. Answers should include the following. • The radical form of the equation is r  D 5 a

Mp

B Ms

Mp2 . B Ms2

r  D5

2

b

72. C

or

Multiply the

fraction under the radical by

Ms3 Ms3

.

Mp2 Ms3  B Ms2 Ms3

r  D5

Mp2 Ms3 B Ms5

 D5 D 

5 2 Mp2Ms3 5 2 Ms5

5 D2 Mp2Ms3

Ms

The simplified radical form is r

5 D2 Mp2 Ms3

Ms

.

• If Mp and Ms are constant, then r increases as D increases because r is a linear function of D with positive slope. ©Glencoe/McGraw-Hill

128

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74. 2x 0 y 0 2x

73. C 75. 36 22

76. 222

78. 4 0 x  5 0

77. 8 79.

1 2 x 2

80. 1440

81. x  2

82. 2x  3

83. x  22x  1

84. 4x  122x  9

Lesson 5-8

Radical Equations and Inequalities Pages 265–267

1. Since x is not under the radical, the equation is a linear equation, not a radical equation. The solution is x

2. The trinomial is a perfect square in terms of 1x . x  61x  9  (1x  3)2, so the equation can be written as (1x  3)2  0. Take the square root of each side to get 1x  3  0. Use the Addition Property of Equality to add 3 to each side, then square each side to get x  9.

23  1 . 2

3. Sample answer: 2x  2x  3  3

4. 2

5. 9

6. no solution

7. 15

8. 18 3 2

10.  x 39

9. 31 11. 0 b 4

12. about 13.42 cm

13. 16

14. 49

15. no solution

16. no solution

17. 9

18. 5

19. 1

20.

21. 20

22. 5

©Glencoe/McGraw-Hill

129

27 2

Algebra 2

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23. no solution

24. 9

25. x  1

26. 2 x 1

27. x 11

28. y  4

29. no solution

30. 4

31. 3

32. no solution

33. 0 x 2

34. 0 a 3

35. b 5

36. c  

37. 3

38. 16

39. 1152 lb

40. t 

41. 34 ft

42. 21.125 kg

43. Since 1x  2 0 and 12x  3 0, the left side of the equation is nonnegative. Therefore, the left side of the equation cannot equal 1. Thus, the equation has no solution.

44. If a company’s cost and number of units manufactured are related by an equation involving radicals or rational exponents, then the production level associated with a given cost can be found by solving a radical equation. Answers should include the following. 3 • C  102n 2  1500

79 16

4 2r 3 B GM

2

• 10,000  10n 3  1500

C  10,000

8500  10n 2

850  n 3 3

8502  n

2 3

Subtract 1500 from each side. Divide each side by 10. Raise each side to the 3 power. 2

24,781.55  n

Use a calculator.

Round down so that the cost does not exceed $10,000. The company can make at most 24,781 chips.

©Glencoe/McGraw-Hill

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45. D

46. C

3 7

1

48. (x  7)2

47. 5

50. 6 0 x 3 0 y 22y

2

49. (x 2  1)3 3

51.

2 100 10

52. 28  10 23 54. 4  x

53. x  y  7, 30x  20y  160; (2, 5) y 30x  20y  160 (2, 5)

x y 7

x

O

55. 1  y

56. 2  4x

57. 11

58. 4  6z  2z 2

59. 3  10x  8x 2

Lesson 5-9 Complex Numbers Pages 273–275 1a. true 1b. true

2. all of them

3. Sample answer: 1  3i and 1  3i

4. 6i

5. 5i 0 xy 0 22

6. 12

7. 18023

8. i 10. 42  2i

9. 6  3i 11.

7 17



11 i 17

12. 3i

13. 2i22

14. i25

15. 3, 3

16. 5, 4

17. 10  3j amps

18. 12i

©Glencoe/McGraw-Hill

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20. 8x 2i

19. 9i

21. 10a 2 0 b 0 i

22. 1322

23. 12

24. 48i

25. 75i

26. i

27. 1

28. 1

29. i

30. 9  2i

31. 6

32. 2

33. 4  5i

34. 25

35. 6  7i

36. 8  4i

37. 8  4i

38.

2 5

40.

39 17

39.

10 17

41.

2 5



6 i 17

1 5

43. 20  15i 1 3



14 i 17

42. 163  16i

 i

45.  

6 5

 i

44.

2 22 i 3

11 14



5 23 i 14

46. (j  4)x 2  (3  i )x  2  4i

47. (5  2i )x 2  (1  i )x  7  i

48. i

49. 4i

50. i 26

51. 2i 23

52. i 23

53. 2i 210

54. 3i 25

55. 

25 i 2

56. 4, 5 7 2

58.  , 3

57. 4, 3 59.

5 , 3

61.

67 19 , 11 11

60. 3, 1

4

62. 5  2j ohms 64. 4  2j amps

63. 13  18j volts

©Glencoe/McGraw-Hill

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65. Case 1: i  0 Multiply each side by i to get i 2  0  i or 1  0. This is a contradiction. Case 2: i 0 Since you are assuming i is negative in this case, you must change the inequality symbol when you multiply each side by i. The result is again i 2  0  i or 1  0, a contradiction. Since both possible cases result in contradictions, the order relation “ ” cannot be applied to the complex numbers.

66. Some polynomial equations have complex solutions. Answers should include the following. • a and c must have the same sign. • i

67. C

68. C

69. 1, i, 1, i, 1, i, 1, i, 1

70. Examine the remainder when the exponent is divided by 4. If the remainder is 0, the result is 1. If the remainder is 1, the result is i. If the remainder is 2, the result is 1. And if the remainder is 3, the result is i.

71. 12

72. 11

73. 4

74. x 15

7

1

75. y 77. c

1 3

76.

2 1 2 d 3 2 1

©Glencoe/McGraw-Hill

a4 a

78. c

133

1 0 d 0 1

Algebra 2

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2 1 2 d 3 2 1

79. c

80.

y

B' x

O

C' A'

81. sofa: $1200, love seat: $600, coffee table: $250

82.

y

y  2x  2 O

x

yx1

83.

84.

y

1 10

xy1 x  2y  4

O

x

85. 0

©Glencoe/McGraw-Hill

134

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Chapter 6 Quadratic Functions and Inequalities Lesson 6-1 Graphing Quadratic Functions Pages 290–293 2a. (2, 1); x  2 2b. (3, 2); x  3

1. Sample answer: f (x )  3x 2  5x  6; 3x 2, 5x, 6 3a. up; min. 3b. down; max. 3c. down; max. 3d. up; min.

4a. 0; x  0; 0 4b.

x f(x) 1 4 0 0 1 4

p

4c.

f (x) O (0, 0)

x f (x)  4x 2

5a. 0; x  1; 1

6a. 1; x  2; 2

5b.

6b.

x f(x) 3 3 2 0 1 1 0 0 1 3

p

5c.

6c.

f(x)

x 0 1 2 3 4

p

f(x) 1 2 3 2 1

f(x) (2, 3)

O f (x)  x 2  2x

©Glencoe/McGraw-Hill

O

f (x)  x 2  4x  1

x

x

(1, 1)

135

Algebra 2

Chapter 6

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7a. 3; x  4; 4

8a. 1; x  1; 1

7b.

8b.

x f(x) 1 7 1 0 1 1 2 1 3 7

8c.

f(x)

x f(x) 6 9 5 12 4 13 3 12 2 9

p

7c.

f(x) 10

8

4

p

x

O 4

f (x)  2x 2  4x  1

8 2

O

f (x)  x  8x  3

12 (4, 13)

5 3

5 3

9a. 0; x   ;  9b.

x 3 2

(1, 1)

x

10. max.; 7

f(x) 3 8

5 3

25 3





1 0

7 0

9c.

f(x) 4 2

4

O

2

x

4

(

)

 5 ,  25 3

3

8 f (x)  3x 2  10x 12

25 4

11. min.; 

©Glencoe/McGraw-Hill

12. min.; 0

136

Algebra 2

Chapter 6

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14a. 0; x  0; 0

13. $8.75

14b.

x f(x) 2 8 1 2 0 0 1 2 2 8

p

14c.

f (x)

f (x )  2x 2 (0, 0)

x

O

15a. 0; x  0; 0

16a. 4; x  0; 0

15b.

16b.

x f(x) 2 20 1 5 0 0 1 5 2 20

p

15c.

x f(x) 2 8 1 5 0 4 1 5 2 8

p

16c.

f(x)

f(x)

O f (x )  5x

2

(0, 0)

12

x

8 (0, 4) f (x )  x 2  4 4

2

O

17a. 9; x  0; 0

18a. 4; x  0; 0

17b.

18b.

x 2 1 0 1 2

p

f(x) 5 8 9 8 5

©Glencoe/McGraw-Hill

137

x 2 1 0 1 2

p

2

4x

f(x) 4 2 4 2 4 Algebra 2

Chapter 6

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17c.

18c.

f(x)

f(x)

4 4

2

4x

2

O

x

O

4 (0, 9)

f (x )  2x 2  4

f (x )  x 2  9

19a. 191; x  0; 0

20a. 4; x  2; 2

19b.

20b.

x f(x) 2 13 4 1 0 1 1 4 2 13

p

19c.

20c.

f (x)

f (x )  3x 2  1

x 0 1 2 3 4

p

f(x) 4 1 0 1 4

f(x)

f (x )  x 2  4x  4

(0, 1) x

O

(0, 4)

O

x

(2, 0)

21a. 9; x  4.5; 4.5

22a. 5; x  2; 2

21b.

22b.

21c.

x 3 4 4.5 5 6

p

f(x) 9 11 11.25 11 9

p

f(x) 5 8 9 8 5

22c.

f(x)

f(x) x

O

2 O

x 0 1 2 3 4

4

8

12

x

4 8 12

©Glencoe/McGraw-Hill

f (x )  x 2  9x  9 f (x )  x 2  4x  5

(4 12 , 1114 )

(2, 9)

138

Algebra 2

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23a. 36; x  6; 6

24a. 1; x  1; 1

23b.

24b.

x f(x) 8 4 7 1 6 0 5 1 4 4

p

23c.

x 3 2 1 0 1

p

f(x) 8 1 4 1 8

24c.

f(x) 6

f(x) f (x )  3x 2  6x  1

4 2

f (x )  x  12x  36

16 12

8 4 (6, 0)

O x

(1, 4)

2 3

2 3

25a. 3; x  2, 2

26a. 0; x   , 

25b.

26b.

x 0 1 2 3 4

25c.

p

f(x) 3 3 5 3 3

f(x)

x 2 1

26c.

(2, 5)

f(x) 4 1

2 3

4 3

0 1

0 7



O

5 4

28a. 1; x  0; 0

27a. 0; x   ; 

©Glencoe/McGraw-Hill

x

f (x )  3x 2  4x

x

5 4

f(x)

( 23 , 43 )

f (x )  2x 2  8x  3

O

x

O

2

139

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27b.

x 3 2

28b.

f(x) 3 2

5 4

x 2

25 8





1 0

0

3 0

27c.

p

1

p

1 2

f(x) 1 1 2



1 1 2



1

28c.

f(x)

f(x) f (x )  0.5x 2  1

f (x )  2x 2  5x O x

O x (0, 1)

( 54 ,  258) 29a. 0; x  6; 6

30a.

29b.

30b.

29c.

x 8 7 6 5 4

f(x) 8 8.75 9 8.75 8

p

(6, 9)

8

9 ; 2

x  3, 3

x 5 4 3 2 1

p

f(x) 2 0.5 0 0.5 2

30c.

f(x)

f(x)

4 8

4

O

x

(3, 0)

4

f (x )  1 x 2  3x  9

f (x )  0.25x 2  3x

©Glencoe/McGraw-Hill

2

140

O

x

2

Algebra 2

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8 9

1 1 3 3

31a.  ; x  ; 31b.

x

f(x)

1

7 9 8  9

0 1 3

1

1



32. min.; 0

5 9 7 1 9

2 31c.

f(x)

2

2

8

f (x )  x  3 x  9 O x

(

1 , 1 3

)

33. max.; 9

34. min.; 14

35. min.; 11

36. max.; 5

37. max.; 12

38. min.;

7 8

9 2

39. max.; 

40. max.; 5

41. min.; 11

42. max.; 5

43. min.; 10

1 3

44. x  40; (40, 40)

45. 40 m

46. 300 ft, 2.5 s

47. The y-intercept is the initial height of the object.

48. 120  2x

49. 60 ft by 30 ft

50. 1800 ft2

51. $11.50

52. $2645

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53. 5 in. by 4 in.

54. c; The x-coordinate of the 0 vertex of y  ax 2  c is  2a or 0, so the y-coordinate of the vertex, the minimum of the function, is a(0)2  c or c ; 12.5

55. If a quadratic function can be used to model ticket price versus profit, then by finding the x-coordinate of the vertex of the parabola you can determine the price per ticket that should be charged to achieve maximum profit. Answers should include the following. • If the price of a ticket is too low, then you won’t make enough money to cover your costs, but if the ticket price is too high fewer people will buy them. • You can locate the vertex of the parabola on the graph of the function. It occurs when x  40. Algebraically, this is found

56. C

by calculating x  

b 2a

which, for this case, is 4000 x or 40. Thus the 2(50)

ticket price should be set at $40 each to achieve maximum profit. 57. C

58. 2.08

59. 3.20

60. 0.88

61. 3.38

62. 0.43

63. 1.56

64. 1

65. 1  3i

66. 9  5i

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67. 23

68. 13

69. 4

70. [10 4 5] 28 20 44 d 72. c 8 16 36

71. [5 13 8] 6 73. C 14

0

24

2 3

8



S

74.

y y  3x yx4

(1, 3)

O

x

(1, 3); consistent and independent 75. 5

76. 8

77. 2

78. 1

Lesson 6-2

Solving Quadratic Equations by Graphing Pages 297–299 2. Sample answer: f (x)  3x 2  2x  1; 3x 2  2x  1  0

1a. The solution is the value that satisfies an equation. 1b. A root is a solution of an equation. 1c. A zero is the x value of a function that makes the function equal to 0. 1d. An x-intercept is the point at which a graph crosses the x-axis. The solutions, or roots, of a quadratic equation are the zeros of the related quadratic function. You can find the zeros of a quadratic function by finding the x-intercepts of its graph.

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3. The x-intercepts of the related function are the solutions to the equation. You can estimate the solutions by stating the consecutive integers between which the x-intercepts are located.

4. 4, 1

5. 2, 1

6. 4

7. 7, 0

8. 4, 6

9. 7, 4

10. 5

11. between 2 and 1, 3

12. between 1 and 0; between 1 and 2

13. 2, 7

14. 0, 6

15. 3

16. 2, 1

17. 0

18.  , 3

19. no real solutions

20. 0, 3

21. 0, 4

22. between 5 and 4; between 0 and 1

23. between 1 and 0; between 2 and 3

24. 4, 5

25. 3, 6

26. 7

27. 6

28. 1 , 3

1 2

1 2

1 2

1 2

29.  , 2

1 2

1 2

30. 4, 1

˛

1 2

31. 2 , 3

32. between 4 and 3; between 0 and 1

33. between 0 and 1; between 3 and 4

34. between 1 and 0, between 2 and 3

35. between 3 and 2; between 2 and 3

36. no real solutions

37. no real solutions

38. 8, 9

˛

©Glencoe/McGraw-Hill

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40. Let x be the first number. Then, 9  x is the other number. x(9  x)  24 2 x  9x  24  0

39. Let x be the first number. Then, 7  x is the other number. x(7  x)  14 2 x  7x  14  0

y

y 2

y  x  7x  14 O

O

x

y  x  9x  24

Since the graph of the related function does not intersect the x-axis, this equation has no real solutions. Therefore, no such numbers exist.

Since the graph of the related function does not intersect the x-axis, this equation has no real solutions. Therefore, no such numbers exist. 41. 2, 14

42. 4 s

43. 3 s

44. about 12 s

45. about 35 mph

46. about 8 s

©Glencoe/McGraw-Hill

x

2

145

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47. 4 and 2; The value of the function changes from negative to positive, therefore the value of the function is zero between these two numbers.

48. Answers should include the following. • h (t ) 2 h (t )  16t  185

180

160 140 120 100 80 60 40 20 0

1

2 3 4 5 t

• Locate the positive x-intercept at about 3.4. This represents the time when the height of the ride is 0. Thus, if the ride were allowed to fall to the ground, it would take about 3.4 seconds. 49. A

50. B

51. 1

52. 3

53. 3, 5

54. 9, 1

55. 1.33

56. no real solutions

57. 4, x  3; 3

58. 1; x  1; 1 f (x)

f(x)

(1, 3)

f (x)  4x 2  8x  1 x

O

O

x

f (x)  x 2  6x  4 (3, 5)

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59. 4; x  6; 6

60.

1 5

62.

1 13

3 5

 i

f(x) 8 f (x)  1 x 2  3x  4 4

4 O 12 8

4

x 4

(6, 5)

61.

10 13



2 i 13



5 i 13

63. 24

64. 8

65. 60

66. $500

67. x(x  5)

68. (x  10)(x  10)

69. (x  7)(x  4)

70. (x  9)2

71. (3x  2)(x  2)

72. 2(3x  2)(x  3)

Lesson 6-3

Solving Quadratic Equations by Factoring Pages 303–305

1. Sample answer: If the product of two factors is zero, then at least one of the factors must be zero.

2. Sample answer: roots 6 and 5; x 2  x  30  0

3. Kristin; the Zero Product Property applies only when one side of the equation is 0.

4. {0, 11}

5. {8, 2}

6. {7, 7}

7. {3}

8. e , 4 f 3 4

10. x 2  3x  28  0

9. {3, 4} 11. 6x 2  11x  4  0

12. 15x 2  14x  3  0

13. D

14. {8, 3}

15. {4, 7}

16. {5, 5}

17. {9, 9}

18. {6, 3}

©Glencoe/McGraw-Hill

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19. {3, 7}

20. e 0, f

21. e 0,  f

22. {6}

23. {8}

24.

5 3

3 4

25.

e

1 , 4

e2,

1 f 4

26. e ,  f

4f

1 2

3 2

27. e ,  f

28. e ,  f

29. e ,

30. {2, 4}

31. {3, 1}

32. 0, 6, 5

33. 0, 3, 3

34. x 2  9x  20  0

35. x 2  5x  14  0

36. x 2  x  20  0

37. x 2  14x  48  0

38. 2x 2  7x  3  0

39. 3x 2  16x  5  0

40. 12x 2  x  6  0

41. 10x 2  23x  12  0

42.

43. 14, 16

44. 12 cm by 16 cm

45. B  D 2  8D  16

46. 4; The logs must have a diameter greater than 4 in. for the rule to produce positive board feet values.

47. y  (x  p)(x  q) y  x 2  px  qx  pq y  x 2  (p  q)x  pq a  1, b  (p  q), c  pq axis of symmetry:

48. 1

2 3

8 3

3 2

3 9 f 4 4

1 4

2 3

s

b 2a (p  q)  2(1) pq 2

x x x

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The axis of symmetry is the average of the x-intercepts. Therefore the axis of symmetry is located halfway between the x-intercepts. 49. 6

50. Answers should include the following. • Subtract 24 from each side of x 2  5x  24 so that the equation becomes x 2  5x  24  0. Factor the left side as (x  3) (x  8). Set each factor equal to zero. Solving each equation for x. The solutions to the equation are 3 and 8. Since length cannot be negative, the width of the rectangle is 3 inches, and the length is 3  5 or 8 inches. • To use the Zero Product Property, one side of the equation must equal zero.

51. D

52. B

53. 5, 1

54. 

55. between 1 and 0; between 3 and 4

56. min.; 19

57. 322  223

58. 523

59. 33  20 22

60. (4, 4)

61. (3, 5)

62. a , 2b

63. 222

64. 225

65. 323

66. 5i 22

67. 2i 23

68. 4i23

1 2

1 3

˛

˛

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Chapter 6 Practice Quiz 1 Page 305 1. 4; x  2; 2

2. max.;

f(x) 4 O

37 4

or 9

1 4

f (x)  3x 2  12x  4 4

8

12

x

4 8

(2, 8)

4. e 5, f 1 2

1 2

3. 1 , 4 5. 3x 2  11x  4  0

Lesson 6-4 Completing the Square Pages 310–312 1. Completing the square allows you to rewrite one side of a quadratic equation in the form of a perfect square. Once in this form, the equation is solved by using the Square Root Property.

2. Never; the value of c that makes ax 2  bx  c a perfect square trinomial is

3. Tia; before completing the square, you must first check to see that the coefficient of the quadratic term is 1. If it is not, you must first divide the equation by that coefficient.

4. {10, 4}

5. e 7.

b

the square of and the 2 square of a number can never be negative.

4  22 f 3

9 , ax 4

6. 36; (x  6)2

3 2 2

 b

8. {6, 3}

9. 54  256 ©Glencoe/McGraw-Hill

10. 51  i 256 150

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11. e

3  233 f 4

12. Jupiter 14. {3, 7}

13. Earth: 4.5 s, Jupiter: 2.9 s 15. {2, 12}

16. 54  27, 4  276

17. 53  2226

18. e

19. e

5  211 f 3

7  25 f 2

20. e  , 5 4

1 f 4

21. {1.6, 0.2}

22. 25 ft

23. about 8.56 s

24. 64; (x  8)2

25. 81; (x  9)2

26.

27.

49 ; ax 4

7 2 2

 b

25 , ax 16



15 2 b 2

28. 0.09; (x  0.3)2

29. 1.44; (x  1.2)2 31.

225 ; ax 4

30.

5 2 4

 b

16 ; ax 9

4 2 3

 b

32. {3, 5}

33. {12, 10}

34. 51  276

37. {3  2i}

38. e  , 1 f

39. e , 1 f 1 2

40. e

5  213 f 6

41. e

2  210 f 3

42. e

7  i 247 f 4

43. e

5  i 123 f 6

44. {2, 0.6}

35. 52  236

36. 52  i 6 5 2

45. {0.7, 4}

46. e  23 f

47. e  22 f

48. 5

1 3

3 4

49.

x 1 , 1 x1

©Glencoe/McGraw-Hill

50.

151

1 2

in. by 5

1 2

in.

1  25 2

Algebra 2

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51. Sample answers: The golden rectangle is found in much of ancient Greek architecture, such as the Parthenon, as well as in modern architecture, such as in the windows of the United Nations building. Many songs have their climax at a point occurring 61.8% of the way through the piece, with 0.618 being about the reciprocal of the golden ratio. The reciprocal of the golden ratio is also used in the design of some violins.

52a. n  0 52b. n  0 52c. n  0

53. 18 ft by 32 ft or 64 ft by 9 ft

54. To find the distance traveled by the accelerating race car in the given situation, you must solve the equation t 2  22t  121  246 or t 2  22t  125  0. Answers should include the following. • Since the expression t 2  22t  125 is prime, the solutions of t 2  22t  121  246 cannot be obtained by factoring. • Rewrite t 2  22t  121 as (t  11)2. Solve (t  11)2  246 by applying the Square Root Property. Then, subtract 11 from each side. Using a calculator, the two solutions are about 4.7 and 26.7. Since time cannot be negative, the driver takes about 4.7 seconds to reach the finish line.

55. D

56. D

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57. x 2  3x  2  0

58. x 2  6x  27  0

59. 3x 2  19x  6  0

60. 12x 2  13x  3  0

61. between 4 and 3; between 0 and 1

62. 6, 8

1 2

3

63. 4, 1

64. 57

65. (2, 5)

66. a , b 43 6 21 7

67. 0 x  (257)0  2

68. greatest: 255C; least: 259C

69. 37

70. 16

71. 121

72. 0

Lesson 6-5

The Quadratic Formula and the Discriminant Pages 317–319

1a. Sample answer:

2. The square root of a negative number is a complex number.

y

x

O

1b. Sample answer: y

O

©Glencoe/McGraw-Hill

x

153

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1c. Sample answer: y

O

x

3. b 2  4ac must equal 0.

4a. 484 4b. 2 rational 4c.

2  22 2

1 2

6c. 

8. 0, 8

7a. 3 7b. two complex 7c.

3  i 23 2

9. 3, 2 11.

5 2



6a. 0 6b. one rational

5a. 8 5b. 2 irrational 5c.

1 , 4

10. 1  23

5  i 22 2

12. at about 0.7 s and again at about 4.6 s

13. No; the discriminant of 16t 2  85t  120 is 455, indicating that the equation has no real solutions.

14a. 21 14b. 2 irrational

15a. 240 15b. 2 irrational 15c. 8  2215

16a. 16 16b. 2 complex 16c. 1  2i

17a. 23 17b. 2 complex

18a. 121 18b. 2 rational

17c.

14c.

1  i 223 2

1 2 4 3

18c.  ,

19a. 49 19b. 2 rational ©Glencoe/McGraw-Hill

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20a. 20 20b. 2 irrational 154

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19c. 2,

1 3

20c. 2  25

21a. 24 21b. 2 irrational

22a. 0 22b. one rational

21c. 1  26

22c.

23a. 0 23b. one rational

24a. 31 24b. 2 complex

5 2

1 3

9  i 231 8 28 9

23c. 

24c.

25a. 135

26a.

25b. 2 complex

26b. 2 irrational

1  i 215 4

25c.

26c.

2  4 27 9

28. 2, 32

27a. 1.48 27b. 2 irrational 1  2 20.37 0.8

27c.

29. i

221 7

30. 2  i 23

31.

3  215 2

32. 22

33.

9 2

34. 3  i 27

35.

5  246 3

36. 4  27

3 10

37. 0, 

38. 3  222

39. 2, 6

40.

41. This means that the cables do not touch the floor of the bridge, since the graph does not intersect the x-axis and the roots are imaginary.

42. domain: 0 t 25, range: 73.7 A(t ) 1201.2

43. 1998

44. about 40.2 mph

©Glencoe/McGraw-Hill

155

 0.00288

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45a. k  6 45b. k  6 or k  6 45c. 6  k  6

46. The person’s age can be substituted for A in the appropriate formula, depending upon their gender, and their average blood pressure calculated. See student’s work. • If a woman’s blood pressure is given to be 118, then solve the equation 118  0.01A2  0.05A  107 to find the value of A. Use the Quadratic Formula, substituting 0.01 for a, 0.05 for b, and 11 for c. This gives solutions of about 35.8 or 30.8. Since age cannot be negative, the only valid solution for A is 30.8.

47. D

48. C

49. 14, 4

50. 4  27

51.

1  2 22 2

52. 2, 0 2 , 3

53. 2, 7

54.

55. a 4b10

56. 10p6 0 q 0

5

58. 7.98 106

57. 4b 2c 2 59.

60.

y

y x1

xy9 8 yx4 6 4 2 6 4

O 4 6

yx

2 4 6 8 xy  3

x

x

O

y  1

61. no

62. yes; (x  7)2

63. yes; (2x  3)2

64. yes; (5x  2)2

65. no

66. yes; (6x  5)2

©Glencoe/McGraw-Hill

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Lesson 6-6

Analyzing Graphs of Quadratic Functions Pages 325–328

1a. 1b. 1c. 1d. 1e.

y  2(x  1)2  5 y  2(x  1)2 y  2(x  3)2  3 y  2(x  2)2  3 Sample answer: y  4(x  1)2  3 1f. Sample answer: y  (x  1)2  3 1g. y  2(x  1)2  3

2. Substitute the x-coordinate of the vertex for h and the y -coordinate of the vertex for k in the equation y  a(x  h)2  k. Then substitute the x-coordinate of the other point for x and the y-coordinate for y into this equation and solve for a. Replace a with this value in the equation you wrote with h and k.

3. Sample answer: y  2(x  2)2 1

4. Jenny; when completing the square is used to write a quadratic function in vertex form, the quantity added is then subtracted from the same side of the equation to maintain equality.

5. (3, 1); x  3; up

6. y  (x  4)2  19, (4, 19); x  4; up

7. y  3(x  3)2  38; (3, 38); x  3; down

8.

y

y  3(x  3)2 O x

9.

10.

y

y

O

y   2x 2  16x  31 x

1 y  3 (x  1)2  3

O

x

12. y  (x  3)2  6

11. y  4(x  2)2 ©Glencoe/McGraw-Hill

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1 2

13. y   (x  2)2  3

14. h(d )  2d 2  4d  6

15. (3, 0); x  3 down

16. (1, 2); x  1; up

17. (0,6); x  0 up

18. (0, 3); x  0; down

19. y  (x  2)2  12; (2, 12); x  2; down

20. y  (x  3)2  8; (3, 8); x  3; up

21. y  3(x  2)2  12; (2, 12); x  2; down

22. y  4(x  3)2  36; (3, 36); x  3; up

23. y  4(x  1)2  7; (1, 7); x  1; up

24. y  2(x  5)2  15; (5, 15); x  5; down

1 2 2

3 2 2

25. y  3 ax  b  ; 1 a , 2

26. y  4 ax  b  20;

7 4

 b; x   ; up 7 4

3 a , 2

1 2

27.

20b; x  , up 3 2

28.

y

y O

y  4(x  3)2  1

29.

y  (x  5)2  3

x

x

O

30.

y

y

x

O

1 y  4 (x  2)2  4

31.

1 y  2 (x  3)2  5

x

O

32.

y

y

O x

y  x 2  8x  18 O

x

y  x 2  6x  2

©Glencoe/McGraw-Hill

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33.

y

34.

y  4x 2  16x  11

y y  5x 2  40x  80 x

O

x

O

35.

36.

y

y

y   1 x 2  5x  27 2 2 x

O

O

x

y  1 x 2  4x  15 3

37. Sample answer: the graph of y  0.4(x  3)2  1 is narrower than the graph of y  0.2(x  3)2  1.

38. Sample answer: the graphs have the same shape, but the graph of y  2(x  4)2  1 is 1 unit to the left and 5 units below the graph of y  2(x  5)2  4

39. y  9(x  6)2  1

40. y  3(x  4)2  3

2 3

42. y  3(x  5)2  4

41. y   (x  3)2

5 2

1 3

43. y  x 2  5

44. y  (x  3)2  2

45. y  2x 2

46. y  (x  3)2  4

47. 34,000 feet; 32.5 s after the aircraft begins its parabolic flight

48. about 1.6 s

49. d (t )  16t 2  8t  50

50. about 2.0 s

51. Angle A; the graph of the equation for angle A is higher than the other two since 3.27 is greater than 2.39 or 1.53.

52. Angle B; the vertex of the equation for angle B is farther to the right than the other two since 3.57 is greater than 3.09 or 3.22.

©Glencoe/McGraw-Hill

4 3

159

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53.

y  ax 2  bx  c

54. All quadratic equations are a transformation of the parent graph y  x 2. By identifying these transformations when a quadratic function is written in vertex form, you can redraw the graph of y  x 2. Answers should include the following. • In the equation y  a(x  h)2  k, h translated the graph of y  x 2 h units to the right when h is positive and h units to the left when h is negative. The graph of y  x 2 is translated k units up when k is positive and k units down when k is negative. When a is positive, the graph opens upward and when a is negative, the graph opens downward. If the absolute value of a is less than 1, the graph will be narrower than the graph of y  x 2, and if the absolute value of a is greater than 1, the graph will be wider than the graph of y  x 2. • Sample answer: y  2(x  2)2  3 is the graph of y  x 2 translated 2 units left and 3 units down. The graph opens upward, but is narrower than the graph of y  x 2.

y  a ax 2  xb  c b a

b 2 2a

y  a cx 2  x  a b d  b a

b 2 2a

c  aa b y  a ax 

b 2 b 2a

c

b2 4a

The axis of symmetry is x  h or 

b . 2a

55. D

©Glencoe/McGraw-Hill

56. B

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58. 225; 2 rational

57. 12; 2 irrational

60. 55  2226

59. 23; 2 complex 61. 53  3i 6 63. 2t 2  2t 

62. e 3 t1

2  213 f 2

64. t 2  2t  1

65. n 3  3n 2  15n  21

66. y 3  1 

67a. Sample answer using (1994, 76,302) and (1997, 99,448): y  7715x  15,307,408 67b. 161,167

68. yes

69. no

70. yes

4 y3

71. no

Chapter 6 Practice Quiz 2 Page 328 1. 57  2236

2. e

3. 11; 2 complex

4. 100; 2 rational

5. e

9  5 25 f 2

6. e

7. y  1x  22 2  5 2 3

2  2i 22 f 3

8. y  (x  4)2  2; (4, 2), x  4; up

9. y  1x  62 2; 16, 02, x  6; down

©Glencoe/McGraw-Hill

1  3i f 2

10. y  2(x  3)2  5; (3, 5), x  3; up

161

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Lesson 6-7

Graphing and Solving Quadratic Inequalities Pages 332–335

1. y 1x  32 2  1

2. Sample answer: one number less than 3, one number between 3 and 5, and one number greater than 5

3a. x  1, 5 3b. x 1 or x 5 3c. 1 x 5

4.

y

O

5.

12 8 4 4

2

4 8 12

y

y  2x 2  4x  3

x

y

O

20

7.

6.

y

y  x 2  10x  25

2

4x

O

x

y  x 2  16

8. x  1 or x  5

y  x 2  5x  6

12 8 4 2

O

2

4

6x

9. 5x 0 1  x  76

10. 5x 0 x  3 or x  46

12. 5x 0  23 x 236

11.

©Glencoe/McGraw-Hill

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13. about 6.1 s

14.

y 15 5 8

4

5

O

8x

4

15

y  x 2  3x  18

25

15.

y

16.

y  x 2  7x  8

y

12 8 4 4

O

17.

4

x

8

y  x 2  4x  4

18.

y

5 8

O

x

O

y

4 O

8x

4

10

x

20 30

y  x 2  4x

y  x 2  36

19.

20.

y

y  x 2  3x  10

14

y

10 O

x

6 2 6

y  x 2  6x  5

©Glencoe/McGraw-Hill

163

4

2 O

2x

Algebra 2

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21.

y  x 2  7x  10

22.

y

y y  x 2  10x  23

20 12

x

O 4 12 8

23.

y

4

O 4

4x

24.

y  x 2  13x  36

y 4

6 2 O

2 2

6

10

x

2

O

4

x

4

4

8

y  2x 2  3x  5

8

25.

26. 5

y

x

O

y  2x 2  x  3

27. 2 x 6

28. x  3 or x  3

29. x  7 or x  3

30. 5x 0 x  3 or x  66

33. 5x 0 x 6 or x 46

34. 5x 0 4 x 36

31. 5x 0 7  x  46

32. 5x 0 1 x 56

35. 5x 0 x 7 or x 16

36. e x ` x  38.

37. all reals

39. 5x 0 x  76

40. all reals

42. 5x 0 4  x  1 or x  36

41.

43. 0 to 10 ft or 24 to 34 ft

©Glencoe/McGraw-Hill

1 f 3

44a. 0.98, 4.81; The owner will break even if he charges $0.98 or $4.81 per square foot. 164

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44b. 0.98  r  4.81; The owner will make a profit if the rent is between $0.98 and $4.81. 44c. 1.34  r  4.45; If rent is set between $1.34 and $4.45 per sq ft, the profit will be greater than $10,000 44d. r  1.34 or r  4.45; If rent is set between $0 and $1.34 or above $4.45 per sq ft, the profit will be less than $10,000. 45. The width should be greater than 12 cm and the length should be greater than 18 cm

46. P(n)  n[15  1.5(60  n)]  525 or 1.5n 2  105n  525

47. 6

48. $1312.50; 35 passengers

49.

50. Answers should include the following. • 16t 2  42t  3.75  10 • One method of solving this inequality is to graph the related quadratic function h(t )  16t 2  42t  3.75  10. The interval(s) at which the graph is above the x-axis represents the times when the trampolinist is above 10 feet. A second method of solving this inequality would be to find the roots of the related quadratic equation 16t 2  42t  3.75  10  0 and then test points in the three intervals determined by these roots to see if they satisfy the inequality. The interval(s) at which the inequality is satisfied represent the times when the trampolinist is above 10 feet.

y y  x 2  4

O

x y  x2  4

©Glencoe/McGraw-Hill

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51. C

52. A

55. 5x 0 x  9 or x  36

56. 5x 0 x 3.5 or x 2.56

53. 5x 0 all reals, x 26

54. 5x 0 7  x  76

57. 5x 0 1.2 x 0.46

58. no real solutions

60. y  21x  42 2; 14, 02, x  4; down

59. y  (x  1)2  8; (1, 8), x  1; up 1 2

61. y  (x  6)2; (6, 0),

62. 4, 8

x  6; up 63.

5  i 23 2

64.

65. 4a 2b 2  2a 2b  4ab 2  12a 7b 67. xy 3  y 

66. 6x 3  4x 2y  13xy 2

1 x

68. 15a 2  14a  3

21 48 R 13 22

70. 354 64

69. B

71. 0x  0.008 0 0.002; 0.078 x 0.082

©Glencoe/McGraw-Hill

3  2 26 3

166

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Chapter 7 Polynomial Functions Lesson 7-1 Polynomial Functions Pages 350–352 1. 4  4x 0; x  x 1

2. Sample answer: Evendegree polynomial functions with positive leading coefficients have graphs in which f (x ) S  as x S  and as x S. Odd-degree polynomial functions with positive leading coefficients have graphs in which f (x ) S  as x S  and f (x ) S  as x S .

3. Sample answer given.

4. Sometimes; a polynomial function with 4 real roots may be a sixth-degree polynomial function with 2 imaginary roots. A polynomial function that has 4 real roots is at least a fourth-degree polynomial.

f (x)

O

x

5. 6; 5

6. 5; 3

7. 21; 3

8. 4; 12

9. 2a 9  6a 312

10. 100a 2  20

11. 6a 3  5a 2  8a  45

12a. f (x ) S  as x S , f (x ) S  as x S  12b. odd 12c. 3

13a. f(x ) S  as x S , f(x ) S  as x S  13b. even 13c. 0

14a. f (x ) S  as x S , f (x ) S  as x S  14b. odd 14c. 1

15. 109 lumens

16. 1; 1

17. 3; 1

18. No, the polynomial contains two variables, a and b.

19. 4; 6

20. 3; 5

©Glencoe/McGraw-Hill

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22. 2; 4

21. No, this is not a polynomial 1

because the term cannot c be written in the form x n, where n is a nonnegative integer. 23. 12; 18

24. 125; 37

25. 1008; 36

26. 166; 50

27. 86; 56

28. 100; 4

29. 7; 4

30. 27a3  3a  1

31. 12a 2  8a  20

32. 3a4  2a 2  5

33. 12a6  4a3  5

34. x 3  3x 2  4x  3

35. 3x 4  16x 2  26

36. 6x 2  44x  90

37. x 6  x 3  2x 2  4x  2

38. 9x 4  12x 2  8x  50

39a. f (x ) S  as x S , f (x ) S  as x S  39b. odd 39c. 3

40a. f (x) S  as x S , f (x) S  as x S  40b. even 40c. 4

41a. f (x) S  as x S , f (x) S  as x S  41b. even 41c. 0

42a. f (x ) S  as x S , f (x ) S  as x S  42b. odd 42c. 5

43a. f (x) S  as x S , f (x) S  as x S  43b. odd 43c. 1

44a. f (x ) S  as x S , f (x ) S  as x S  44b. even 44c. 2

45. 5.832 units

46. even

47. f (x ) S  as x S ; f(x ) S  as x S 

48. Sample answer: Decrease; the graph appears to be turning at x  30 indicating a relative maximum at that point. So attendance will decrease after 2000.

49.

1 2

©Glencoe/McGraw-Hill

50. 1, 0, 4

168

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3 2

51. f(x)  x 3  x 2  2x

52.

8

f (x )

3 2 f (x)  12 x 3  4 2 x  2x

4 2

O

2

x

4 8

53. 4

54. 16 regions

55. 8 points

56. Many relationships in nature can be modeled by polynomial functions; for example, the pattern in a honeycomb or the rings in a tree trunk. Answers should include the following. • You can use the equation to find the number of hexagons in a honeycomb with 10 rings and the number of hexagons in a honeycomb with 9 rings. The difference is the number of hexagons in the tenth ring. • Other examples of patterns found in nature include pinecones, pineapples, and flower petals.

57. C

58. C

60. 5x 0 x  9 or x  76

59. 5x 0 2  x  66

©Glencoe/McGraw-Hill

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61. e x ` 1  x  f 4 5

62.

y y  2(x  2)2  3

x

O

63.

64.

y

y

2 12 8

O

x

2

y  1 (x  5)2  1 3

x

O

y  1 x2  x  3 2

2

4

65. 54 3226

66. e  ,

67. 23,450(1  p); 23,450(1  p)3

68.

7 6

5 f 6 y

y  x2  4

x

O

69.

70.

y

8

y

4 O

8

x

4 O

4

8x

4

1

y  2 x 2  2x  6

y  x 2  6x  5

©Glencoe/McGraw-Hill

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Lesson 7-2

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Graphing Polynomial Functions Pages 356–358

1. There must be at least one real zero between two points on a graph when one of the points lies below the x-axis and the other point lies above the x-axis.

2. 4

3.

4.

f (x)

x O

x

p

3 20

8

2

4

1 0

f (x )  x 3  x 2  4x  4

f(x )

1 2 3

0

f (x )

6 4

4

2 O

0

2

4x

4

0

f(x)  x 3  x 2  4x  4

10

6. between 1 and 0

5. x

p

f(x )

f (x)

8

3 20 2 9 1 2 0 5 1 0 2 5 3 26

f (x)

4 4

2 O

2

4x

x

O

4

f (x )  x 3  x 2  1

8

f (x )  x 4  7x 2  x  5

7. between 2 and 1, between 1 and 0, between 0 and 1, and between 1 and 2

8.

8

f (x)

4

f (x) 4

2

O

2

4x

4 O

8

x

f (x )  x 3  2x 2  3x  5

Sample answer: rel. max. at x  2, rel. min.: at x  0.5

f (x )  x 4  4x 2  2

©Glencoe/McGraw-Hill

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10.

f (x)

C (t ) 12000

8 4 4

2

O

2

Cable TV Systems

10000

4x

4

f (x )  x 4  8x 2  10

Sample answer: rel. max. at x  0, rel. min. at x  2 and at x  2

8000 6000

C(t)  43.2t 2  1343t  790

4000 2000 O

4

t

8 12 16 Years Since 1985

11. rel. max. between x  15 and x  16, and no rel. min.; f(x ) S  as x S , f(x ) S  as x S .

12. The number of cable TV systems rose steadily from 1985 to 2000. Then the number began to decline.

13a.

14a. x

f (x )

p

5 25 4 0 3 9 2 8 1 3 0 0 1 5 2 24

x 4 O 2

2

4x

4 8

8 4 4

2 O

2

4x

4

f (x)  x 3  2x 2 6

14b. between 2 and 1 14c. Sample answer: rel. max. at x  0, rel. max. at x  1

f (x)  x 3  4x 2

13b. at x  4 and x  0 13c. Sample answer: rel. max. at x  0, rel. min. at x  3

©Glencoe/McGraw-Hill

p

2 10 1 3 0 6 1 5 2 6 3 15 4 38

f (x )

f (x )

f (x )

172

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15a.

16a. x

p

f (x )

f (x )

2 18 1 2 0 2 1 0 2 2 3 2 4 18

x

p

5 9 4 7 3 9

x

O

2 3 1 5 0 9 1 3 2 19

f (x)  x 3  3x 2 2

15b. at x  1, between 1 and 0, and between 2 and 3 15c. Sample answer: rel. max. at x  0, rel. min. at x  2

4 8

4

4

O

8x

4 8

f (x )  x 3  5x 2  9

16b. between 5 and 4, between 2 and 1, and between 1 and 2 16c. Sample answer: rel. max. at x  3, rel. min. at x  0 18a.

17a. x

f (x )

f (x )

p

f (x )

f (x )

1 75 0 16 1 3 2 0 3 7 4 0 5 39

x 2 1 0 1 2 3 4 5

4 4

2

O

2

4x

4 8

f (x)  3x 3  20x 2  36x  16

17b. between 0 and 1, at x  2, and at x  4 17c. Sample answer: rel. max. at x  3, rel. min. at x  1

©Glencoe/McGraw-Hill

f (x )

f (x )

p

29 8 1 2 5 4 7 34

x

O

f (x )  x 3  4x 2 2x  1

18b. between 3 and 4 18c. Sample answer: rel. max. at x  0.5, rel. min. at x  2.5

173

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19a.

20a. x

p

x

f (x )

3 73 2 8 1 7 0 8 1 7 2 8 3 73

3 0 2 15 1 0 0 9 1 0 2 15 3 0 4 105

4 4

2

2

O

f (x )

p

f (x )

x

4

f (x)  x 4  8 8

19b. between 2 and 1 and between 1 and 2 19c. Sample answer: no rel. max., rel. min. at x  0

16

f (x )

8 4

2

x

2

O 8 16

f (x )  x 4  10x 2 9

20b. at x  3, x  1, x  1, and x  3 20c. Sample answer: rel. max. at x  0, rel. min. at x  2 and x  2 22a.

21a. x

x

f (x )

p

4 169 3 31 2 7 1 5 0 1 1 1 2 1 3 43

8

3 39 2 5 1 3 0 3 1 5 2 21 3 15 4 67

4 4

2

O

2

4x

4 8

f (x )  x 4  5x 2 2x  1

21b. between 3 and 2, between 1 and 0, between 0 and 1, and between 1 and 2 21c. Sample answer: rel. max. at x  2 and at x  1.5, rel. min. at x  0

©Glencoe/McGraw-Hill

f (x )

p

f (x )

24

f (x )

16 8 4

2

O

2

4x

8

f (x)  x 4  x 3 8x 2 3

22b. between 3 and 2, between 1 and 0, between 0 and 1, and between 3 and 4 22c. Sample answer: rel. max. at x  1.5 and at x  2.5, rel. min. at x  0.

174

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23a.

24a.

x f (x )

p

1 65 0 6 1 1 2 2 3 3 4 10 5 11

x

f (x )

2 1 0 1 2 3

4 2

2

O

4

x

4 8

f (x)  x 4  9x 3  25x 2  24x  6

p

f (x ) 45 4 5 6 7 40

4 2

f (x )

2

O

4

6x

4 8

f (x)  2x 4  4x 3  2x 2  3x  5

24b. between 2 and 1, and between 2 and 3 24c. Sample answer: rel. max. at x  0.5; rel. min. at x  0.5 and at x  1.5

23b. between 0 and 1, between 1 and 2, between 2 and 3, and between 4 and 5 23c. Sample answer: rel. max. at x  2, rel. min. at x  0.5 and at x  4

26a.

25a. f (x )

x f (x )

p

4 77 3 30 2 7 1 2 0 3 1 2 2 55

x f (x )

24

2 1

16

0

8 4

2

O

1

2

2

4x

3

f (x)  x 5  4x 4  x 3  9x 2  3

4

25b. between 4 and 3, between 2 and 1, between 1 and 0, between 0 and 1, and between 1 and 2 25c. Sample answer: rel. max. at x  3 and at x  0, rel. min. at x  1 and at x  1

©Glencoe/McGraw-Hill

5

p

40

88 5

f (x )

20

6 5 20 3 10 269

4

2

O

2

4x

20 40

f (x)  x 5  6x 4  4x 3  17x 2  5x  6

26b. between 2 and 1, between 1 and 0, between 0 and 1, between 2 and 3, and between 4 and 5 26c. Sample answer: rel. max. at x  1 and at x  2, rel. min. at x  0 and at x  3.5

175

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27. highest: 1982; lowest: 2000

28. Rel. max. between 1980 and 1985 and between 1990 and 1995, rel. min. between 1975 and 1980 and between 1985 and 1990; as the number of years increases, the percent of the labor force that is unemployed decreases.

29. 5

30. Sample answer: increase, based on the past fluctuations of the graph

31.

x 0 2 4 6 8 10 B(x) 25 34 40 45 50 54 G(x) 26 33 39 44 49 53

32. The growth rate for both boys and girls increases steadily until age 18 and then begins to level off, with boys averaging a height of 71 in. and girls a height of 60 in.

x 12 14 16 18 20 B(x) 59 64 68 71 71 G(x) 56 59 61 61 60

Average Height (in.)

y

B (x )

70 65 60 55

G (x )

50 45 40 35 30 25 20 0

2

4

6

8 10 12 14 16 18 x Age (yrs)

33. 0 and between 5 and 6

34. 5 s

35. 3 s

36.

y

O

©Glencoe/McGraw-Hill

176

x

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y

37.

x

O

O

x

O

y

39.

y

38.

40. The turning points of a polynomial function that models a set of data can indicate fluctuations that may repeat. Answers should include the following. • To determine when the percentage of foreign-born citizens was at its highest, look for the rel. max. of the graph, which is at t  5. The lowest percentage is found at t  75, the rel. min. of the graph. • Polynomial equations best model data that contain turning points, rather than a constant increase or decrease like linear equations.

x

41. D

42. B

43. 1.90; 1.23

44. 3.41; 0.59

45. 0; 1.22, 1.22

46. 0.52; 0.39, 1.62

47. 24a3  4a 2  2

48. 10c 2  25c  20

49. 8a4  10a 2  4

50. 3x 3  10x 2  11x  6

51. 2x 4  11x 2  16

52. 4x 4  9x 3  28x 2  33x  20

©Glencoe/McGraw-Hill

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54.

y

y  x 2  4x  6

y

x

O

x

O

y  x 2  6x  3

55.

56. (7, 4)

y

x

O 2

y  x  2x

57. (3, 2)

58. (4, 2)

59. (1, 3)

60. 1 ft

61. (x  5)(x  6)

62. (2b  1)(b  4)

63. (3a  1)(2a  5)

64. (2m  3)(2m  3)

65. (t  3)(t 2  3t  9)

66. (r 2  1)(r  1)(r  1)

Lesson 7-3 Solving Equations Using Quadratic Techniques Pages 362–364 1. Sample answer: 16x 4  12x 2  0; 4[4(x 2)2  3x 2]  0

2. The solutions of a polynomial equation are the points at which the graph intersects the x-axis.

3. Factor out an x and write the equation in quadratic form so you have x[(x 2)2  2(x 2)  1]  0. Factor the trinomial and solve for x using the Zero Product Property. The solutions are 1, 0, and 1.

4. not possible

©Glencoe/McGraw-Hill

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5. 84(n 2 )2  62(n 2)

6. 0, 5, 4

7. 4, 1, 4, 1

8. 6, 3  3i13, 3  3i13

9. 64

10. 8 feet

11. 2(x 2)2  6(x 2)  10

12. not possible

13. 11(n 3 )2  44(n 3)

14. b[7(b 2)2  4(b 2 )  2)]

15. not possible

16. 6 (x 5 )2  4 (x 5 )  16  0

17. 0, 4, 3

18. 0, 1, 5

19. 13, 13, i 13, i 13

20. 0, 4, 4, 4i, 4i

21. 2, 2, 212, 212

22. 12, 12, 3, 3

23. 9,

1

9  9i 13 9  9i 13 , 2 2

1

24. 8, 4  4i13, 4  4i13

25. 81, 625

26. 343, 64

27. 225, 16

28. 400

29. 1, 1, 4

30. 8, i 23, i 23

31. w  4 cm, /  8 cm, h  2 cm

32. x 4  7x 2  9  27

33. 3 3 in.

34. 6 6 in.

35. h 2  4, 3h  2, h  3

36. The height increased by 3, the width increased by 2, and the length increased by 4.

37. Write the equation in quadratic form, u 2  9x  8  0, where u  |a  3|. Then factor and use the Zero Product Property to solve for a; 11, 4, 2, and 5.

38. Answers should include the following. • Solve the cubic equation 4x 3  (164x 2)  1600x  3600 in order to determine the dimensions of the cut square if the desired volume is 3600 in3. Solutions are 10 in. and 31 2601 2

in. • There can be more than one square cut to produce the same volume because the height of the box is not specified and 3600 has a variety of different factors. ©Glencoe/McGraw-Hill

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39. D

40.

41.

42. x

f (x )

f (x )

p

2 21 1 1 0 5 1 3 2 1 3 1 4 9 5 35

O

x

1715 ; 3

p

f (x )

f (x )

1 15 0 3 1 1 2 3 3 3 4 25

x

x

O

f (x)  x 4  6x 3  10x 2  x  3

f (x)  x 3  4x 2  x  5

44. 262; 2 2 3 3 46. B R 1 3 1 y 48.

43. 17; 27 45.

1 18

135

47. A¿(1, 2), B¿(3, 3), C¿(1, 3)

C' A O

C x

A' B

B' 64 x2

49. x 2  5x  4

50. 4x 2  16x  27 

51. x 3  3x 2  2

52. x 3  2x 2  10x 15 

©Glencoe/McGraw-Hill

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Chapter 7 Practice Quiz 1 Page 364 1. 2a3  6a 2  5a  1

2. f(x ) S  as x S , f(x ) S  as x S ; odd; 3

3. Sample answer: maximum at x  2, minimum at x  0.5

4. (6x 3)2  3(6x 3)  5 or 3 3 36(2x)2  18(2x)  5

8

1

1

f (x )

4 4

2

O

4x

2

4 8

f (x)  x 3  2x 2  4x  6

5. 3, 3, i13, i13

Lesson 7-4

The Remainder and Factor Theorems Pages 368–370

1. Sample answer: f(x )  x 2  2x  3

2. 4

3. dividend: x 3  6x  32; divisor: x  2; quotient: x 2  2x  10; remainder: 12

4. 7, 91

5. 353, 1186

6. x  1, x  3

7. x  1, x  2

8. 2x  1, x  4

9. x  2, x 2  2x  4

10. $2.894 billion

11. $2.894 billion

12. Sample answer: Direct substitution, because it can be done quickly with a calculator.

13. 9, 54

14. 37, 19

15. 14, 42

16. 55, 272

©Glencoe/McGraw-Hill

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17. 19, 243

18. 267, 680

19. 450, 1559

20. 422, 3110

21. x  1, x  2

22. x  4, x  2

23. x  4, x  1

24. x  3, x  1

25. x  3, x 

1 2

26. x  1, x 

or 2x  1

4 3

or 3x  4

27. x  7, x  4

28. x  1, x  6

29. x  1, x 2  2x  3

30. 2x  3, 2x  3, 4x 2  9

31. x  2, x  2, x 2  1

32.

33. 3

34. 8

35. 1, 4

36. 3

37.

5 1 14 69 140 100 5 45 120 100 1 9 24 20 0

1 4 29 24 8 32 24; 1 4 3 0 (x  3)(x  1) 8

38. Yes; 2 ft lengths. The binomial x  2 is a factor of the polynomial since f (2)  0.

39. 7.5 ft/s, 8 ft/s, 7.5 ft/s

40. 0; The elevator is stopped.

41. By the Remainder Theorem, the remainder when f(x ) is divided by x  1 is equivalent to f(1), or a  b  c  d  e. Since a  b  c  d  e  0, the remainder when f (x ) is divided by x  1 is 0. Therefore, x  1 is a factor of f(x ).

42. $31.36

43. $16.70

44. B(x)  2000x 5  340(x 4  x 3  x 2  x  1)

©Glencoe/McGraw-Hill

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45. No, he will still owe $4.40.

46. Using the Remainder Theorem you can evaluate a polynomial for a value a by dividing the polynomial by x  a using synthetic division. Answers should include the following. • It is easier to use the Remainder Theorem when you have polynomials of degree 2 and lower or when you have access to a calculator. • The estimated number of international travelers to the U.S. in 2006 is 65.9 million.

47. D

48. x  2, x  2, x  1, x 2  1

49. (x 2)2  8(x 2)  4

50. 9(d 3)2  5(d 3)  2

51. not possible

52. Sample answer: rel. max, at x  0.5, rel. min. at x  3.5 f (x ) 16 f (x)  x 3  6x 2  4x  3 8 2

O

2

4

x

8 16

54. T 

53. Sample answer: maximum at x  1, rel. max. at x  1.5, rel. min. at x  1

2 2mrFc Fc

f (x ) 8 4 4

2

O

2

4x

4

f (x)  x 4  2x 3  3x 2  7x  4

©Glencoe/McGraw-Hill

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55. (4, 2)

56. (3, 1)

57. A

58. C

59. S

60.

7 117 2

62.

3 i 17 4

61.

9 157 6

Lesson 7-5 Roots and Zeros Pages 375–377 1. Sample answer: p(x )  x 3  6x 2  x  1; p(x ) has either 2 or 0 positive real zeros, 1 negative real zero, and 2 or 0 imaginary zeros.

2. An odd-degree function approaches positive infinity in one direction and negative infinity in the other direction, so the graph must cross the x-axis at least once, giving it at least one real root.

3. 6

4. 2i, 2i; 2 imaginary

5. 7, 0, and 3; 3 real

6. 2 or 0; 1; 2 or 0

7. 2 or 0; 1; 2 or 4

8. 4, 1  2i, 1  2i 10. 2i, 2i, 3

9. 2, 1  i, 1  i

12. f (x )  x 3  2x 2  16x  32

11. 2  3i, 2  3i, 1 8 3

5 i 271 ; 4

13.  ; 1 real

14.

15. 0, 3i, 3i; 1 real, 2 imaginary

16. 3i, 3i, 3i, and 3i; 4 imaginary

17. 2, 2, 2i, and 2i; 2 real, 2 imaginary

18. 2, 2, 0, 2, and 2, 5 real

19. 2 or 0; 1; 2 or 0

20. 2 or 0; 1; 2 or 0

21. 3 or 1; 0; 2 or 0

22. 1; 3 or 1; 2 or 0

23. 4, 2, or 0; 1; 4, 2, or 0

24. 5, 3, or 1; 5, 3, or 1; 0, 2, 4, 6, or 8

25. 2, 2  3i, 2  3i

26. 4, 1  i, 1  i

©Glencoe/McGraw-Hill

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2 imaginary

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27. 2i, 2i,

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i 2



28. 5i, 5i, 7

3 2

1 , 2

29.  , 1  4i, 1  4i

30.

31. 4  i, 4  i, 3

32. 3  i, 3  i, 4, 1

33. 3  2i, 3  2i, 1, 1

34. 5  i, 5  i, 1, 6

35. f(x )  x 3  2x 2  19x  20

36. f(x )  x 4  10x 3  20x 2  40x  96

37. f(x )  x 4  7x 2  144

38. f(x )  x 5  x 4  13x 3  13x 2  36x  36

39. f(x )  x 3  11x 2  23x  45

40. f(x)  x 3  10x 2  32x  48

41a.

42. (3  x)(4  x)(5  x)  24

f (x )

x

O

41b.

4  5i, 4  5i

f (x )

x

O

41c.

f (x )

O

©Glencoe/McGraw-Hill

x

185

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43. 1 ft

44. V(r )  r 3  17 r 2

45. radius  4 m, height  21 m

46. 1; 2 or 0; 2 or 0

47. 24.1, 4.0, 0, and 3.1

48. Nonnegative roots represent times when there is no concentration of dye registering on the monitor.

[30, 10] scl: 5 by [20, 20] scl: 5

49. Sample answer: f(x)  x 3  6x 2  5x  12 and g(x)  2x 3  12x 2  10x  24 each have zeros at x  4, x  2, and x  3.

50. One root is a double root. Sample graph: f (x )

O

©Glencoe/McGraw-Hill

186

x

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51. If the equation models the level of a medication in a patient’s bloodstream, a doctor can use the roots of the equation to determine how often the patient should take the medication to maintain the necessary concentration in the body. Answers should include the following. • A graph of this equation reveals that only the first positive real root of the equation, 5, has meaning for this situation, since the next positive real root occurs after the medication level in the bloodstream has dropped below 0 mg. Thus according to this model, after 5 hours there is no significant amount of medicine left in the bloodstream. • The patient should not go more than 5 hours before taking their next dose of medication.

52. A

53. C

54. 127, 41

55. 254, 915

56. 36 in.

57. min.; 13

58. max.; 32

59. min.; 7

60. 5ab 2(3a  c 2)

61. (6p  5)(2p  9) 3 2 63. C 3 4 S 2 9

62. 4y (y  3)2 11 5 64. C 7 0S 4 5

©Glencoe/McGraw-Hill

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29 8 65. £ 8 9§ 16 16 1 2

2 3

66. y   x  1

5 2

68.

67. , 1, , 5 1 9

1 , 14

1 16

1 3

1 7

2 7

1 2

1 8

1 4

1 2

, , , 1, 2

70. , , , , 1, 2, 4

69. , , 1, 3

Lesson 7-6 Rational Zero Theorem Pages 380–382 1. Sample answer: You limit the number of possible solutions.

2. Sample answer: 2x 2  x  3

3. Luis; Lauren found numbers q p in the form , not as p q Luis did according to the Rational Zero Theorem.

4. 1, 2, 5, 10

1 2

1 3

1 6

2 3

5. 1, 2, , , ,

6. 4, 2, 7

7. 2, 4, 7

8. 2, 2, 3, 3

9. 2, 2,

7 2

10.

2 3 217 , 3 4

11. 10 cm 11 cm 13 cm

12. 1, 2

13. 1, 2, 3, 6

14. 1, 3, 5, 15, ,

15. 1, 2, 3, 6, 9, 18

16. 1, , 3

1 3

1 3

1 3

1 9

17. 1, , , 3, 9, 27

18. 6, 5, 10

19. 1, 1, 2

20. 1, 1

21. 0, 9

22.

23. 0, 2, 2

24. 0, 3

25. 2, 4

26. 7, 1, 3

©Glencoe/McGraw-Hill

5 3

188

1 , 2

1, 1

Algebra 2

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1 , 2

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1 3

1 1 2 5

 , 2

28.  , , 2

1 1 1 3 2 3 2 4

30. 2, ,

4 3 i 3 2

29.  , , , 31.

4 , 5

0,

5 i 13 2

2 3 213 3 2

2 3

32. 3, ,  , 1 3

4 3

33. 1, 2, 5, i, i

34. V  r 3  r 2

35. 2, 2 i 13; 2

36. r  2 in., h  6 in.

37. V  2h3  8h 2  64h

38. /  36 in., w  48 in., h  32 in.

˛

˛

1 3

1 3

39. V  / 3  3/ 2

40. 6300  /3  3/2

41. /  30 in., w  30 in., h  21 in.

42. k  3; 3, 6, 5

43. The Rational Zero Theorem helps factor large numbers by eliminating some possible zeros because it is not practical to test all of them using synthetic substitution. Answers should include the following. • The polynomial equation that represents the volume of the compartment is V  w 3  3w 2  40w. • Reasonable measures of the width of the compartment are, in inches, 1, 2, 3, 4, 6, 7, 9, 12, 14, 18, 21, 22, 28, 33, 36, 42, 44, 63, 66, 77, and 84. The solution shows that w  14 in., /  22 in., and d  9 in.

44. D

45. Sample answer: x 5  x 4  27x 3  41x 2  106x  120

46. 6, 3, 5

©Glencoe/McGraw-Hill

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47. 4, 2  i, 2  i

48. 5, 3i, 3i

49. 7, 5  2i, 5  2i

50. 4x  3, 5x  1

51. x  4, 3x 2  2

52. 725

54. 0 4x  5 0

53. 3xy 22x 55. 6 cm, 8 cm, 10 cm

56. x 3  4x 2  6

57. 4x 2  8x  3

58. x 3  5x 2  x  10

59. x 5  7x 4  8x 3  106x 2  85x  25

60. x  9 

61. x 2  x  4 

33 x7

5 x1

Chapter 7 Practice Quiz 2 Page 382 1. 930, 145

2. 0, 180

3. x 4  4x 3  7x 2  22x  24  0

4.

4 5

3 2

5. 

Lesson 7-7

Operations on Functions Pages 386–389

1. Sometimes; sample answer: If f(x )  x  2, g(x )  x  8, then f  g  x  6 and g  f  x  6.

2. Sample answer: g(x )  {(2, 1), (1, 2), (4, 3)}, f (x )  {(1, 7),(2, 9), (3, 3)}

3. Danette; [g  f ](x )  g [f (x )] means to evaluate the f function first and then the g function. Marquan evaluated the functions in the wrong order.

4. 4x  9; 2x  1; 3x 2  19x  20; 3x  4,

©Glencoe/McGraw-Hill

x 5

190

x5

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5. x 2  x  1; x 2  x  7; x 3  4x 2  3x  12; x2  3 , x4

6. {(5, 7), (4, 9)}; {(4, 12)}

x 4

7. {(2, 7)}; {(1, 0), (2, 10)}

8. 6x  8; 6x  4

9. x 2  11; x 2  10x  31

10. 30

11. 11

12. 1 3 4

13. p(x )  x; c (x )  x  5

14. $32.49; price of CD when 25% discount is taken and then the coupon is subtracted

15. $33.74; price of CD when coupon is subtracted and then 25% discount is taken

16. Discount first, then coupon; sample answer: 25% of 49.99 is greater than 25% of 44.99. 18. 6x  6; 2x  12; 8x 2  6x  27;

17. 2x ; 18; x 2  81;

x9 , x9

x 9

2x  3 , 4x  9

19. 2x 2  x  8; 2x 2  x  8; 2x 3  16x 2;

21.

2x 2 , 8x

20. x 2  8x  15; x 2  4x  3; 2x 3  18x 2  54x  54;

x 8

x3 , 2

x3  x2  1 , x 1 x1 x 3  x 2  2x  1 , x1

22.

x 3

x 3  x 2  7x  15 , x 2; x2 x 3  x 2  9x  9 , x 2; x2

x 2  6x  9, x 2; x 2  4x  4, x 2, 3

x 1; x 2  x ; x 1 x3  x2  x  1 , x

9 4

x 

x 0

23. {(1, 3), (3, 1), (2, 1)}; {(1, 0), (0, 1)}

24. {(2, 4), (4, 4)}; {(1, 5), (3, 3), (5, 3)}

25. {(0, 0), (8, 3), (3, 3)}; {(3, 6), (4, 4), (6, 6), (7, 8)}

26. {(4, 5), (2, 5), (6, 12), (8, 12)}; does not exist

27. {(5, 1), (8, 9)}; {(2, 4)}

28. {(2, 3), (2, 2)}; {(5, 6), (8, 6), (9, 5)}

©Glencoe/McGraw-Hill

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29. 8x  4; 8x  1

30. 15x  5; 15x  1

31. x 2  2; x 2  4x  4

32. 3x 2  4; 3x 2  24x  48

33. 2x 3  2x 2  2x  2; 8x 3  4x 2  2x  1

34. 2x 2  5x  9; 2x 2  x  5

35. 12

36. 50

37. 39

38. 68

39. 25

40. 48

41. 2

42. 1

43. 79

44. 104

45. 226

46. 36

47. P(x )  50x  1939

48. 939,000

49. p(x )  0.70x; s(x )  1.0575x

50. s[p(x )]; The 30% would be taken off first, and then the sales tax would be calculated on this price.

51. $110.30

52. [K  C](F ) 

53. 373 K; 273 K

54. 309.67 K

55. $700, $661.20, $621.78, $581.73, $541.04

56. 244

57. Answers should include the following. • Using the revenue and cost functions, a new function that represents the profit is p(x )  r(c(x )). • The benefit of combining two functions into one function is that there are fewer steps to compute and it is less confusing to the general population of people reading the formulas.

58. A

59. C

60. 1, 2, 4, 8

©Glencoe/McGraw-Hill

1 2

192

5 9

(F  32)  273

Algebra 2

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3 2

1 3

61. 1, , , 2, 3, ,

1 9

62. 1, ,

3 , 6 4

63. x 3  4x 2  17x  60

64. x 3  3x 2  34x  48

65. 6x 3  13x 2  9x  2

66. x 3  6x 2  4x  24

67. x 3  9x 2  31x  39

68. x 4  x 3  14x 2  26x  20 5 6 1 70.  B R 2 7 8 72. does not exist

69. 10  2j 3 2 71. c d 1 1 1 2

1 2 R 3 4

75. 

1 16

B

76. x 

6  3y 2

77. y 

1  4x 2 5x

78. x 

2 3  7y

79. t 

I pr

80. F  C  32

73.  B

74. does not exist

5 2 R 3 2

81. m 

9 5

Fr 2 GM

Lesson 7-8

Inverse Functions and Relations Pages 393–394

1. no

2. Switch x and y in the equation and solve for y.

3. Sample answer: f (x)  2x, f 1(x)  0.5x; f [f 1(x )]  f 1[f (x )]  x

4. n is an odd whole number.

5. {(4, 2), (1, 3), (8, 2)}

6. {(3, 1), (1, 1), (3, 1), (1, 1)}

©Glencoe/McGraw-Hill

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1 3

8. g 1(x )  x 

7. f 1(x )  x 4

f (x )

4

2

g (x )

f (x)  x f 1(x )  x

2 O

g (x )  3x  1 2

4x

2

4

2

2

O

2

4x

2

g1(x)  13 x  13

4

9. y  2x  10 12

1 3

10. yes

y y  1x  5 2

8 4 O

4

4

8

y

1

12

x

 2x 10

11. no

12. 32.2 ft/s2

13. 15.24 m/s2

14. {(6, 2), (5, 4), (1, 3)}

15. {(8, 3), (2, 4), (3, 5)}

16. {(4, 7), (5, 3), (4, 1), (5, 7)}

17. {(2, 1), (2, 3), (4, 1), (6, 0)}

18. {(11, 6), (7, 2), (3, 0), (3, 5)}

19. {(8, 2), (5, 6), (2, 8), (6, 5)}

20. x  3 y 4 x  3 2 4

2 O

2

4x

2 4

©Glencoe/McGraw-Hill

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y  3

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1 2

22. f 1(x )  x  5

21. g1(x )   x g (x )

4

f 1(x)  x  5

g (x )   12 x 2 1

2

x

x 4

2

O

2

4

4

2 O

g (x )  2x

24. f 1(x )  x  1

g (x ) 4

f (x ) 4

2 g (x )  x  4 O

2

2 f (x)  3x  3 4x

4

g1(x)  x2 4

2 O

4

1 2

1 2

25. y   x  1

2

y 1  3x

  1x  1 2 2

O

f 1(x)  13 x 1

2

4

y

2 4

4x

2

O

2

4x

2

2 y  2x  1 4

©Glencoe/McGraw-Hill

4x

26. y  3x

y

4

4

2

2

4

y

4

1 3

23. g1(x )  x  4

2

2

2 f (x)  x  5 4

2

4

f (x )

4

y  13 x

195

4

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8 5

27. f 1(x )  x

28. f 1(x )  3x  12 f (x ) 8 7 f (x)  1 x  4 3 6 5

f (x )

4 2 4

2

O

4x

2

3 2 1

f (x)  58 x

2 4

O

1 2 3 4 5 6 7 8x

f 1(x )  3x  12

f 1(x)  85 x

5 4

29. f 1(x )  x 

35 4

30. g1(x )  3x 

f (x)1  54 x  35 4 40

4

f (x ) x O 30 20 10

4

4

2

O

20

2

30

4

f (x)  45 x  7 40

8 7

g (x )

g (x)  2x 6 32

10

31. f 1(x )  x 

3 2

2

4x

g1(x)  3x  32

4 7

32. yes

f (x )

f 1(x)  87 x 2 47 4

2

O 2

2

4x

f (x)  7x 8 4

4

33. no

34. no

35. yes

36. yes

37. yes

38. y  1 2

39. y  x 

©Glencoe/McGraw-Hill

11 2

4(x  7)  6 2

40. 12

196

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9 5

42. C 1(x )  x  32;

41. I(m)  320  0.04m; $4500

C [C1(x )]  C 1[C (x )]  x 43. It can be used to convert Celsius to Fahrenheit.

44. Sample answer: f(x )  x and f 1(x )  x or f(x )  x and f 1(x )  x

45. Inverses are used to convert between two units of measurement. Answers should include the following. • Even if it is not necessary, it is helpful to know the imperial units when given the metric units because most measurements in the U.S. are given in imperial units so it is easier to understand the quantities using our system. • To convert the speed of light from meters per second to miles per hour, 3.0 108 meters  1 second 3600 seconds 1mile  1 hour 1600 meters

46. A

f (x) 



675,000,000 mi/hr 47. B

48. g [h(x)]  4x  20; h[g(x)]  4x  5

49. g[h(x )]  6x  10; h[g(x )]  6x

50. g [h(x)]  x 2  3x  24; h[g(x)]  x 2  5x  24

51. 7, 2, 3

52.  , ,

53. 64

54. 32

55. 3

56. 4

57. 117

58. 196

©Glencoe/McGraw-Hill

1 4 5 4 3 2

197

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60. 

59. 7 61.

25 4

Lesson 7-9

Square Root Functions and Inequalities Pages 397–399

1. In order for it to be a square root function, only the nonnegative range can be considered.

2. Both have the shape of the graph of y  2x, but y  2x  4 is shifted down 4 units, and y  2x  4 is shifted to the right 4 units.

3. Sample answer: y  22x  4

4.

8 7 6 5 4 3 2 1

y

y  x  2 1 2 3 4 5 6 7 8x

O

D: x  0, R: y  2 5.

8 7 6 5 4 3 2 1

6.

y

4

y  3  x 2

x y  4x

O

O

8

12

1 2 3 4 5 6 7 8x

D: x  0; R: y  0 8 7 6 5 4 3 2 1

4

2

O

7.

y

D: x  0; R: y  3 8.

y

y  x  1  3

1 2 3 4 5 6 7 8x

8 7 6 5 4 3 2 1 O

y

y x  4  1

1 2 3 4 5 6 7 8x

D: x  1; R: y  3 ©Glencoe/McGraw-Hill

198

Algebra 2

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9.

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8

12:02 PM

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10.

y

6

y  2x  4

4

1 O

O

11.

4 3 2 1 2

O

2

y

4

y y  3  5x  1 1 2 3 4 5 6 7x

2 3 4

2 2

4 3 2 1

6x

12. v  22gh

y  x  2  1

1 2 3 4 5 6x

2 3 4

14.

13. Yes; sample answer: The advertised pump will reach a maximum height of 87.9 ft.

8 7 6 5 4 3 2 1

y

y  3x 1 2 3 4 5 6 7 8x

O

D: x  0, R: y  0 15.

16.

y O 1 2 3 4 5 6 7 8

1 2 3 4 5 6 7 8x

y  5x

1 2 3 4 5 6 7 8x

y  4x

D: x  0, R: y  0

D: x  0, R: y  0

©Glencoe/McGraw-Hill

y O 1 2 3 4 5 6 7 8

199

Algebra 2

Chapter 7

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17.

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18.

y

8 7 6 5 4 3 2 1

2

2 2

1 2 3 4 5 6 7 8x

20.

1 2 3 4 5 6 7 8x

D: x  7, R: y  0

1 2 3 4 5 6 7 8x

y  2x  1

22.

4

y

2

x

O 4

6

y  5x  3

8

D: x  6, R: y  3 24.

y

6 4

y  5 x  4

2 O 2

2

4x

8 7 6 5 4 3 2 1 O

D: x  4, R: y  5

©Glencoe/McGraw-Hill

2

y  x  6  3 4

1 2 3 4 5 6 7 8x

23.

2 2

D: x  0.6, R: y  0

4

6x

4

D: x  0.5, R: y  0

y

O

2

y O 1 2 3 4 5 6 7 8

y  x  7

O

O

D: x  2, R: y  0

y

8 7 6 5 4 3 2 1

8 7 6 5 4 3 2 1

y  x  2

4

y  1 x

D: x  0, R: y  0

21.

y

6

O

19.

8

y

y  3x  6  4

1 2 3 4 5 6 7 8x

D: x  2, R: y  4

200

Algebra 2

Chapter 7

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25.

8

Page 201 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-07:

26.

y

y O

y  23  4x  3 6 4 2 3

2

1

x

O

1 2 3 4 5 6 7 8x 2 4 6 8 10 12 y  6x 14 16

D: x  0.75, R: y  3 27.

8

y  x  5

28.

y

8

6

6

4

4

2

2 O

4

29.

8 7 6 5 4 3 2 1 O

31.

8 7 6 5 4 3 2 1 O

2

y

y  2x  8

O 2

x

4

30.

y

y  5x  8 1 2 3 4 5 6 7 8x

8 7 6 5 4 3 2 1 O

2

2

4x

y

y  x  3  4

1 2 3 4 5 6 7 8x

32. 125 ft

y

y  6x  2  1

1 2 3 4 5 6 7 8x

33. 317.29 mi

34. 119 lb

35. See students’ work.

36. If a is negative, the graph is reflected over the x-axis. The larger the value of a, the less steep the graph. If h is positive, the origin is

©Glencoe/McGraw-Hill

201

Algebra 2

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translated to the right, and if h is negative, the origin is translated to the left. When k is positive, the origin is translated up, and when k is negative, the origin is translated down. 37. Square root functions are used in bridge design because the engineers must determine what diameter of steel cable needs to be used to support a bridge based on its weight. Answers should include the following. • Sample answer: When the weight to be supported is less than 8 tons. • 13,608 tons

38. C

39. D

40. yes

41. no

42. yes

43. 2x  2; 8; x 2  2x  15;

44. 11x  22; 9x18; 10x 2  40x  40; 10; x 2

45.

x5 ,x 3 x3 8x 3  12x 2  18x  26 , 2x  3 3 x  ; 2 3 8x  12x 2  18x  28 , 2x  3 3 3 x  ; 2x  3, x  ; 2 2

46. 4; If x is your number, you can write the expression 3x  x  8 , x2

which equals 4

after dividing the numerator and denominator by the GCF, x  2.

8x 3  12x 3  18x  27, 3 2

x 

47. 2x 2  4x  16

48. 6p 2  2p  20

49. a3  1

©Glencoe/McGraw-Hill

202

Algebra 2

Chapter 7

Chapter 8 Conic Sections Lesson 8-1 Midpoint and Distance Formulas Pages 414–416 1. Since the sum of the x-coordinates of the given points is negative, the x-coordinate of the midpoint is negative. Since the sum of the y-coordinates of the given points is positive, the y-coordinate of the midpoint is positive. Therefore, the midpoint is in Quadrant II.

2. all of the points on the perpendicular bisector of the segment

4. a2,

3. Sample answer: (0, 0) and (5, 2)

13 b 2

5. (2.5, 2.25)

6. 10 units

7. 1122 units

8. 12.61 units 10. (12, 5)

9. D 11. (4, 2)

12. (2, 6)

13. a ,

14. (0.075, 3.2)

15. (3.1, 2.7)

16. a ,  b

17. a ,

18. a ,

17 27 b 2 2

1 24

5 12

5 24

1 13 5 b, a , 2 2 2

5 b 8

2b, a5, b 1 2

19. (7, 11)

20. around 8th St. and 10th Ave.

21. Sample answer: Draw several line segments across the U.S. One should go from the NE corner to the SW corner; another should go from the SW corner to the NW corner; another should go across the middle (east to west); and so on. Find the midpoints of these segments. Locate a point to represent all of these midpoints.

22. near Lebanon, Kansas

©Glencoe/McGraw-Hill

203

Algebra 2

Chapter 8

23. See students’ work.

24. 13 units

25. 25 units

26. 12 units

27. 3117 units

28. 0.75 unit

29. 170.25 units

30. 165 units

31. 1 unit

32. 1271 units

33.

1813 12

34. 6110 units, 90 units2

units

35. 712  158 units, 10 units2

36. 165  2 12  1122  1277 units

37. 1130 units

38. about 85 mi

39. about 0.9 h

40. 14 in.

41. The slope of the line through

42. The formulas can be used to decide from which location an emergency squad should be dispatched. Answers should include the following. • Most maps have a superimposed grid. Think of the grid as a coordinate system and assign approximate coordinates to the two cities. Then use the Distance Formula to find the distance between the points with those coordinates. • Suppose the bottom left of the grid is the origin. Then the coordinates of Lincoln are about (0.7, 0.3); the coordinates of Omaha are about (4.6, 3.3); and the coordinates of Fremont are about (1.5, 4.6). The distance from Omaha to Fremont is about

y y

1 (x1, y1) and (x2, y2) is 2 x2  x1 and the point-slope form of the equation of the line is

y2  y1 (x  x1). x2  x1 x  x2 y1  y2 Substitute ¢ 1 , ≤ 2 2

y  y1 

into this equation. The left

y2  y1 . 2 y  y1 The right side is 2 x2  x1 y2  y1 x2  x1 x1  x2 ¢  x1≤  ≤ ¢ x2  x1 2 2 y  y1 or 2 . Therefore, the 2

side is

y1  y2 2

 y1 or

point with coordinates ¢

x1  x2 y1  y2 , ≤ 2 2

lies on the

line through (x1, y1) and (x2, y2). The distance from ¢

x1  x2 y1  y2 , ≤ 2 2

B

¢x1 

or

to (x1, y1) is

y1  y2 2 x1  x2 2 ≤  ¢y1  ≤ 2 2

102(1.5  4.6)2  (4.6  3.3)2

or 34 miles. The distance from Lincoln to Fremont is

y1  y2 2 x1  x2 2 ≤ ¢ ≤ . The B 2 2 ¢

©Glencoe/McGraw-Hill

204

Algebra 2

Chapter 8

distance from ¢

x1  x2 y1  y2 , ≤ 2 2

about 102(1.5  0.7)2  (4.6  0.3)2

to (x2, y2) is B

¢x1 

or 44 miles. Since Omaha is closer than Lincoln, the helicopter should be dispatched from Omaha.

y1 y2 x1  x2 b  ¢y2  ≤  2 2 2

2

y2  y1 2 x2  x1 2 ≤ ¢ ≤ B 2 2 ¢

or

y1  y2 2 x1  x2 2 ≤ ¢ ≤. B 2 2 ¢

Therefore, the point with coordinates ¢

x1  x2 y1  y2 , ≤ 2 2

is equidistant from (x1, y1) and (x2, y2). 43. C

44. B

45. on the line with equation y  x

 ¿ is perpendicular to 46. 1; AA the line with equation y  x, which has slope 1. 48. D  5x 0 x  06, R  5y 0  16

47. D  5x 0 x  26, R  5y 0 y  06 y

y

y  兹x  1

y  兹x  2

O

x

x

O

49. D  5x 0 x  06, R  5y 0 y  16

50. no

y

y  2兹x  1

O

x

51. 1  13i

52. 6  2i

53. 4  3i

54. y  (x  3)2

©Glencoe/McGraw-Hill

205

Algebra 2

Chapter 8

55. y  (x  2)2  3

56. y  2(x  5)2

57. y  3(x  1)2  2

58. y  (x  2)2  10

59. y  3(x  3)2  17

Lesson 8-2 Parabolas Pages 423–425 1. (3, 7), a3, 6 b, x  3, 15 16

y 7

2. Sample answer: x y 2

1 16

3. When she added 9 to complete the square, she forgot to also subtract 9. The standard form is y  (x  3)2  9  4 or y  (x  3)2  5.

4. y  2(x  3)2  12

5. (3, 4), a3, 3 b, x  3,

6. (7, 3), a7, 3 b, x  7, 1 8

3 4

1 4

7 8

y  4 , upward, 1 unit

y  2 , upward,

y

1 2

unit

y 16 14 12 10 8 6 4 y  2(x  7)2  3 2

x

O

1412108 6 4 2

y  (x  3) 2  4

©Glencoe/McGraw-Hill

206

2x

Algebra 2

Chapter 8

7. a ,  b, a ,  b, x   , 4 3

y

2 3 7  , 12

4 3

3 4

downward,

y  3x 2  8x  6

8. a , b, a , b, y  ,

4 3

1 3

3 9 2 2

9 9 8 2

15 8

x   , right,

unit

9 2

3 2

units

y

y x

O

x  2 y 2  6y  12 3

x

O

1 8

1 8

9. y  (x  3)2  6

10. x   (y  1)2  5 y

y

8

8

x

O

11. x 

x

O x   1 (y  1) 2  5

y  1 (x  3) 2  6

1 2 y 24

12. y  (x  3)2  2

6

1 2

13. x  (y  7)2  29 5 2

14. y  (x  12)2  80

15. x  3 ay  b  11 6

16. (0, 0), a0,  b, x  0, y  , 3 2

1 12

3 2

downward, 6 units y 6y  x 2 O

©Glencoe/McGraw-Hill

207

x

Algebra 2

Chapter 8

17. (0, 0), a , 0b, y  0, x   ,

18. (6, 3), a6, 3 b, x  6,

1 2

1 2

3 4

1 4

right, 2 units

y  2 , upward, 3 units

y

y y 2  2x x

O

3(y  3)  (x  6)2 O x

19. (1, 4), a1, 3 b, x  1, y  4 , 1 2

1 2

20. (2, 3), (3, 3), y  3, x  1, right, 4 units

downward, 2 units

y

y

x

O

4(x  2)  (y  3)2 O

2(y  4)  (x  1)2

x

22. (6, 16), a6, 15 b, x  6, 3 4

21. (4, 8), (3, 8), y  8, x  5, left, 4 units 16 14 12 10 8 6 4 2 4 321

©Glencoe/McGraw-Hill

1 4

y  16 , upward, 1 unit

y

2 2 4 6 8 10 12 14 16

(y  8)2  4(x  4) O 1 2 3 4x

208

y O2 4 6 8 10 12 14 x

y  x 2  12x  20

Algebra 2

Chapter 8

24. a

5 115 144 ,  b, a , 4 2 5 287 1 x , right, 10 5

23. (24, 7), a23 , 7b, y  7, 3 4

1 4

x  24 , right, 1 unit 24

y

y

x  y 2  14y  25 16

8

8x

O

1 b, 12

5 2

unit

x  5y 2  25y  60

2 1

2 3 4 5 6

8

25. (4, 2), a4, 2

5 2

O 10 20 30 40 50 60 70 80 x

8 24 16

 b, y   ,

26. a ,  b, a , 7b, x  , 5 4

x  4,

11 12

y  1 , upward,

1 3

y

unit

55 5 5 8 4 4 27 1  , downward, unit 4 2 y O

y 2

2

x

4

4 x  2x 2  5x  10 8 12

y  3x 2  24x  50

16

x

O

27. a , b, a , b, y  , 17 3 67 3 4 4 16 4 69 1 x  , left, 4 16

28. (3, 5), a3, 5 b, x  3, y  4 ,

3 4

1 2

1 2

upward, 2 units

unit

y

y x  4y 2  6y  2

y  1 x 2  3x  19

O

2

x

2

O

x

©Glencoe/McGraw-Hill

209

Algebra 2

Chapter 8

29. (123, 18), a122 , 18b, y  18,

1 4 3 x  123 , left, 4

20 120 60

O

30.

y x  3y 2  4y  1

3 units

y

O

x 120x

60

20 40 60

x   1 y 2  12y  15 3

1 3

32. 1 and 

31. 1 33. y  

34. a ,  b

35. 0.75 cm

36. y 

1 3

2 3

2 3

1 2 x 16

1 y

y  1 x2  1 16

x

O

1 (y 24

37. x   y

O

1 8

38. x  (y  2)2  6

 6)2  8

y

14 12 10 8 6 x   1 (y  6)2 8 24 4 2

x

O

x  1 (y  2)2 6 8

1 2 3 4 5 6 7 8x 2

©Glencoe/McGraw-Hill

210

Algebra 2

Chapter 8

39. y 

1 (x 16

1 6

40. y   (x  7)2  4

 1)2  7 8 6 4 2

4 321 2 4 6 8

y

8

y   1 (x  7)2 4 6

y

4

y  1 (x  1)2 7 16

O 12

O1 2 3 4 5 6 x

8

4

x 4

XBox.

8

2 9

1 4

42. y  x 2  2

41. x  (y  3)2  4 y x  1 (y  3)2 4 4

x

O

1 (x 100

44. y  

43. about y  0.00046x 2  325 1 x2 26,200

45. y  

46. x  (y  3)2  4

 6550

47. A parabolic reflector can be used to make a car headlight more effective. Answers should include the following. • Reflected rays are focused at that point. • The light from an unreflected bulb would shine in all directions. With a parabolic reflector, most of the light can be directed forward toward the road.

48. B

49. A

50. 13 units

51. 10 units

52. 234 units

©Glencoe/McGraw-Hill

 50)2  25

211

Algebra 2

Chapter 8

53.

54. 2.016  105

y

O

y 兹x  1

x

55. 4

56. 5

57. 9

58. 12

59. 223

60. 322

61. 423

62. 622

Lesson 8-3 Circles Pages 428–431 1. Sample answer: (x  6)2  (y  2)2  16

2. (x  3)2  (y  1)2  64; left 3 units, up 1 unit

3. Lucy; 36 is the square of the radius, so the radius is 6 units.

4. (x  3)2  (y  1)2  9

5. (x  1)2  (y  5)2  4

6. x 2  (y  2)2  25

7. (x  3)2  (y  7)2  9

8. (4, 1), 3 units y

O

x (x  4)2  (y  1)2  9

©Glencoe/McGraw-Hill

212

Algebra 2

Chapter 8

9. (0, 14), 234 units 24

10. (4, 0),

y

4 5

unit

y

x 2  (y  14)2  34

(x  4)2  y 2  16

16

25

8

x

O 16

8

16x

8

O 8

11. a , b

212 3

2 1 3 2

12. (4, 3), 5 units

unit

y

y

(x  4)2  (y  3)2  25

x

O 2

2

(x  23 )  (y  12 )

 8

O

9

x

14. x 2  y 2  42,2002

13. (2, 0), 223 units y

x

O

(x  2)2  y 2  12

16. (x  1)2  (y  1)2  16

15. y Earth Satellite 35,800 km x 6400 km

©Glencoe/McGraw-Hill

42,200 km

213

Algebra 2

Chapter 8

17. (x  2)2  (y  1)2  4 19. (x  8)2  (y  7)2  1 2 2

21. (x  1)2  ay  b 

18. x 2  (y  3)2  49

1 4

20. (x  1)2  (y  4)2  20

1945 4

22. (x  8)2  (y  9)2  1130

23. (x  213)2  (y  42)2  1777

24. (x  8)2  (y  7)2  64

25. (x  4)2  (y  2)2  4

26. (x  1)2  (y  4)2  16

27. (x  5)2  (y  4)2  25

28. x 2  y 2  18

29. (x  2.5)2  (y  2.8)2  1600

30. (0, 2), 2 units y x 2  (y  2)2  4 O

32. (3, 1), 5 units

31. (0, 0), 12 units 16

y

x

y

x 2  y 2  144

8 16 8

O

8

16x

(x  3)2  (y  1)2  25

8

x

O

16

©Glencoe/McGraw-Hill

214

Algebra 2

Chapter 8

33. (3, 7), 9 units (x  3)2  (y  7)2  81 4 2

34. (3, 0), 4 units y

y

12108642 O2 4 6 8 x 2 4 6 8 10 12 14 16

(x  3)2  y 2  16

35. (3, 7), 522 units 2 64 2 2 4 6 8 10 12 14

x

O

36. (25, 4), 5 units y

y (x  3)2  (y  7)2  50 O 2 4 6 8 10 x

O

x

38. (7, 3), 222 units

37. (2, 23), 229 units y

y O x

O

©Glencoe/McGraw-Hill

x

215

Algebra 2

Chapter 8

40. (1, 0), 211 units

39. (0, 3), 5 units y

y

O

x

O

42. a , 4b, 9 2

41. (9, 9), 2109 units 18 16 14 12 10 8 6 4 2 2O 2

x

y

2129 2

units y

2 4 6 8 10 12 14 16 18 x

43. a , 4b, 3 2

4 2 6 42 2 4 6 8 10 12

©Glencoe/McGraw-Hill

3 217 2

O x

units

44. (6, 8), 4 units

y

16 14 12 10 8 6 4 2

O 2 4 6 8 10 x

2 2

216

y

O 2 4 6 8 10 12 14 x

Algebra 2

Chapter 8

45. (1, 2), 214 units

46. (2, 1), 22 units

y

O

y

x O

47. a0,  b, 219 units 9 2

x

48. about 109 mi

y O

x

49. (x  1)2  (y  2)2  5

50. A circle can be used to represent the limit at which planes can be detected by radar. Answers should include the following. • x 2  y 2  2500 • The region whose boundary is modeled by x 2  y 2  4900 is larger, so there would be more planes to track.

51. A

52. D

53. y  216  (x  3)2

54. y  216  (x  3)2, y  216  (x  3)2

©Glencoe/McGraw-Hill

217

Algebra 2

Chapter 8

56. x  3  216  y 2; The equations with the  symbol and  symbol represent the right and left halves of the circle, respectively.

55.

[10, 10] scl:1 by [10, 10] scl:1

58. (3, 2), a3, 2 b, x  3,

57. (1, 0), a , 0b, y  0, x  1 , left,

1 3

1 4

1 12

11 12

3 4

y  1 , downward, 1 unit

unit y

y O

x  3y 2  1

y  2  (x  3)2

x

x

O

59. (2, 4), a2, 3 b, x 2, 3 4

60. (4, 4)

1 4

y  4 , upward, 1 unit y 2

y  x  4x

O

x

61. (1, 2)

62. a , 6b

63. 4, 2, 1

64.  , 2, 3

65. 28 in. by 15 in.

66. 12

67. 6

68. 4

69. 25

70. 225

3 2

1 2

71. 222 ©Glencoe/McGraw-Hill

218

Algebra 2

Chapter 8

Chapter 8 Practice Quiz 1 Page 431 1. 13 units

2. 2226 units

3. (0, 0), a1 , 0b, y  0,

4. (4, 4), a4, 4 b, x  4,

x

1 2 1 1 , 2

1 4

3 4

y  3 , upward, 1 unit

right, 6 units

y

y y 2  6x x

O

y  x 2  8x  20 O x

5. (0, 4), 7 units 12 10 8 6 4 2 8642O 2 4

©Glencoe/McGraw-Hill

y

2 4 6 8x

x 2  (y  4)2  49

219

Algebra 2

Chapter 8

Lesson 8-4 Ellipses Pages 437–440 1. x  1, y  2

2. Let the equation of a circle be (x  h)2  (y  k)2  r 2. Divide each side by r 2 to get (y  k)2 (x  h)2  r2 r2

1. This

is the equation of an ellipse with a and b both equal to r. In other words, a circle is an ellipse whose major and minor axes are both diameters. 3. Sample answer: (x  4

5.

2)2

(y  4)2 36



(y  1



(x  2)2 4

5)2

4.

x2 36

6.

y2 100

1 1

7. (0, 0): (0, 3); 612; 6



y2 20



1

x2 36

1

8. (1, 2); (5, 2), (3, 2); 415; 4

y

y

O

x

O

y2 x2  1 18 9

x

( y  2)2 (x  1)2  1 4 20

10. (4, 2); (4  216, 2); 10; 2

9. (0, 0); (2, 0); 412; 4

y

y

x

O

x

O 2

2

4x  8y  32

©Glencoe/McGraw-Hill

220

Algebra 2

Chapter 8

11. about

x2 1.32  1015

12.

y2 64

14.

(x  5)2 64



(y  4)2 9

1

16.

(x  2)2 81



(y  5)2 16

1

1

18.

(y  2)2 100



(x  42 2 9

1

1

20.

(x  1)2 81



(y  2)2 56

1

22.

x2 324

24.

x2 193,600



y2 279,312.25

26.

(x  1)2 30



(y  1)2 5



y2 1.27  1015



x2 39

1

1 13.

x2 16



y2 7

15.

y2 16



(x  2)2 4

17.

(y  4)2 64



19.

(x  5)2 64



21.

x2 169



23. about

1

y2 25

1

(x  2)2 4 (y  4)2 81 4

1

x2 2.02  1016



y2 2.00  1016



y2 196

1 1

1 25.

y2 20



x2 4

1

27. (0, 0); (0, 15); 2110; 215

28. (0, 0); (4, 0); 10; 6

y

O

y

x

x

O

y2 x2  1 10 5

©Glencoe/McGraw-Hill

1

x2 y2  1 25 9

221

Algebra 2

Chapter 8

29. (8, 2); (8  3 17, 2); 24; 18 16

30. (5, 11); (5, 11  123); 24; 22

y

4 8

1284 O4 8 12 16 20 x 4 8 12 16 20 24 28 (y  11)2 (x  5)2  1

O 24 16

8

y

8x 8

(x  8) 2 (y  2)2  1 16 144 81

144

121

32. (0, 0); (0,  16); 6; 213

31. (0, 0); (16, 0); 6; 213

y

y

x

O

3x 2  9y 2  27

27x 2  9y 2  81

33. (0, 0); (0, 17); 8; 6

34. (0, 0); (315, 0); 18; 12

y

8 6 4 2 8642 2 4 6 8

x

O

2

x

O

2

16x  9y  144

y

O 2 4 6 8x

36x 2  81y 2  2916

36. (2, 7); (2  412, 7); 4110 ; 412

35. (3, 1); (3, 5), (3, 3); 416; 412 y

12

y

8 4 O O

8

x

4

4

x

4

©Glencoe/McGraw-Hill

222

Algebra 2

Chapter 8

37. (2, 2); (2, 4), (2, 0); 217; 213

38. (1, 3); (2, 3), (4, 3); 10; 8

y

y

x

O

x

O

39.

x2 12



y2 9

1

40. Knowledge of the orbit of Earth can be used in predicting the seasons and in space exploration. Answers should include the following. • Knowledge of the path of another planet would be needed if we wanted to send a spacecraft to that planet. • 1.55 million miles 42. B

41. C 43. about

x2 1.351019



44. (x  3)2  (y  2)2  25

y2 1.26  1019

1 45. (x  4)2  (y  1)2  101

46. (x  1)2  y 2  45

47. (x  4)2  (y  1)2  16

48. y  (x  3)2  1

1 2

y

O

©Glencoe/McGraw-Hill

223

1 2 y  2 (x  3)  1 x

Algebra 2

Chapter 8

49.

50. Sample answer using (0, 104.6) and (10, 112.6): y  0.8x  104.6

People (millions)

Married Americans 120 118 116 114 112 110 108 106 104 0 0 2 4 6 8 10 12 14 16 18 20

51. Sample answer: 128,600,000

52.

y

O

x

y  2x

53.

54.

y

y y   12 x

55.

x

O

x

O

y  2x

56.

y

y

y  12 x

O

x

O

x

y  2  2(x 1)

©Glencoe/McGraw-Hill

224

Algebra 2

Chapter 8

57.

y

O

x y  2  2(x  1)

Lesson 8-5 Hyperbolas Pages 445–448 1. sometimes

3. Sample answer: 5.

x2 1



y2 15

2. As k increases, the branches of the hyperbola become wider. x2 4



y2 9

1

4.

y2 4



x2 21

1

6. (0, 3 22); (0, 238);

1

y

3110 x 10 8 6 4 2

8642 2 4 6 8

©Glencoe/McGraw-Hill

225

y

y2

x2  18 20  1 O2 4 6 8 x

Algebra 2

Chapter 8

7. (1, 6  2 25); (1, 6  3 25); y  6 

8. (6, 0); (237, 0);

2 25 (x 5

1 6

y x  1)

16

y

2 2 8 x  36y  36

x

O

y

16

8

O

8

16x

8 2

(y  6)

2



20

(x  1) 25

16

1

3 4

9. (4  2 25, 2); (4  3 25, 2); y2

25 (x 2

10. (0, 15); (0, 25); y   x 20 15 10 5

 4)

y

16 12 8 4

13.

x2 4



y2 12

ay

11  2b

1 

25 4

15.

x2 25

17.

(x  2)2 49



19.

x2 16

1





12.

(y  3)2 1



(x  2)2 4

1

14.

(x  3)2 4



(y  5)2 9

1

16.

y2 16

1

18.

(y  5)2 16



20.

y2 36

1

2

y2 36

x2 6

y2 9

1

1

©Glencoe/McGraw-Hill

(y  3)2 4

x2  400  1 225 y2

2015105 O5 10 15 20x 5 10 15 20

1284 O4 8 12 16 20 x 4 8 12 16

11.

y

1

226





x2 49

x2 4

(x  4)2 81

1

Algebra 2

Chapter 8

21. (9, 0); ( 2130, 0);

22. (0, 6); (0, 2210); y 3x

7 9

y x

8 6 4 2

2 2 y x  y 1 81 49 16 12 8 4

4 5

24. (3, 0); ( 234, 0); y   x

y

y x2

y2  9 25  1

8 6 42 O2 4 6 8 x 2 4 6 8 y2 x2  16 25  1

26. (2, 0); (222, 0); y  x y

22  x 2

x 2  y 2 4

y x 2  2y 2  2

©Glencoe/McGraw-Hill

x

O

25. ( 22, 0); (23, 0);

O

x2  4 1

5 3

23. (0, 4); (0, 241); y   x

y

y2 36

4 3 21 O1 2 3 4 x 2 4 6 8

161284 O4 8 12 16x 4 8 12 16

8 6 4 2

y

O

x

x

227

Algebra 2

Chapter 8

27. (0, 6); (0, 3 25); y  2x 16

28. (0, 22); (0, 222);

y

y

23 x 3

8

y y 2  36  4x 2

8

16

4

16x

8

O

6y 2  2x 2  12

12

30. (2, 2), (2, 8); (2, 3  241);

29. (2, 0), (2, 8); (2, 1),

5 4

4 3

y  3   (x  2)

(2, 9); y  4   (x  2) 12

y

y 10 8 (x  2)2 (y  36)2 1  4 16 25 2 O 2 4 6 8 10 x 6 42 2 4 6

8 )2

(y  4 16

8

(x  2)2

 49 O 4

1 4

x

4

31. (3, 3), (1, 3);

32. (12, 3), (0, 3);

(1  213, 3); y3

x

O

3  (x 2

(6  3 25, 3); 1 2

 1)

y  3   (x  6)

y O

6 4 2

x

y

O 2x 1412108 6 42 2 4 6 2 (y  3)8 (x  6)2  9 10 1 36 (y  3)2 (x  1)2 1  9 4

©Glencoe/McGraw-Hill

228

Algebra 2

Chapter 8

34. (4, 0), (6, 0); (1  229, 0);

33. (1, 3  2 26);

2 5

(1, 3  4 22);

y   (x  1)

y  3  23(x  1)

8 6 4 2

y 6 4 2 8 6 42 O2 4 6 8 x 2 4 6 8 10

y

8 6 42 O2 4 6 8 x 2 4 4x 2 6 25y 2  8x  96 0 8

y 2  3x 2  6y  6x  18  0

35.

x2 1.1025



y2 7.8975

1

36.

y

Station

38.

37. 120 cm, 100 cm

©Glencoe/McGraw-Hill

229

(x  2)2 4

O



Station x

(y  3)2 4

1

Algebra 2

Chapter 8

39. about 47.32 ft

40. Hyperbolas and parabolas have different graphs and different reflective properties. Answers should include the following. • Hyperbolas have two branches, two foci, and two vertices. Parabolas have only one branch, one focus, and one vertex. Hyperbolas have asymptotes, but parabolas do not. • Hyperbolas reflect rays directed at one focus toward the other focus. Parabolas reflect parallel incoming rays toward the only focus.

41. C

42. B

43.

44. ( 22, 22), (22, 22)

y xy  2

x

O

45.

46. The graph of xy  2 can be obtained by reflecting the graph of xy  2 over the x-axis or over the y-axis. The graph of xy  2 can also be obtained by rotating the graph of xy  2 by 90 .

y xy  2 x O

47.

(x  5)2 16



©Glencoe/McGraw-Hill

(y  2)2 1

1

48.

230

(y  1)2 16



(x  3)2 9

1

Algebra 2

Chapter 8

49.

(x  1)2 25



(y  4)2 9

1

50. (5, 1), 2 units y

x

O

3 2

51. 4, 2 7 0 S 53. C 5 20 55. about 5,330,000 subscribers per year

52. 7,

57. 2x  17y

58. 2, 3, 5

59. 1, 2, 9

60. 3, 1, 2

61. 5, 0, 2

62. 1, 0, 0

54. [13 8 1] 56. 5, 4

63. 0, 1, 0

Chapter 8 Practice Quiz 2 Page 448 1.

(y  1)2 81



(x  3)2 32

1

2. (4, 2); (4  2 22, 2); 6; 2 y

O

x

(y  2)2 (x  4)2 1  1 9

©Glencoe/McGraw-Hill

231

Algebra 2

Chapter 8

3. (1, 1); (1, 1  211); 8;

4.

x2 9



y2 16

1

225 y

x

O

5.

(x  2)2 16



(y  2)2 5

1

Lesson 8-6 Conic Sections Pages 450–452 2. 2x 2  4x  7y  1  0

1. Sample answer: 2x 2  2y 2  1  0

3 2 2

4. y  ax  b  , parabola

3. The standard form of the equation is (x  2)2  (y  1)2  0. This is an equation of a circle centered at (2, 1) with radius 0. In other words, (2, 1) is the only point that satisfies the equation.

5.

y2 16



x2 8

y

8642 2 4 6 8

©Glencoe/McGraw-Hill

x

O

1 2 2

6. ax  b  y 2  , circle

 1, hyperbola 8 6 4 2

5 4

9 4

y

y

O 2 4 6 8x

O

232

x

Algebra 2

Chapter 8

7.

(x  1)2 4



(y  3)2 1

 1,

8. parabola

ellipse y

x

O

9. ellipse 11.

10. hyperbola 12. x 2  y 2  27, circle

y 10 8 6 4 2 2 4 6

8

y

4 O2 4 6 8 10 12 14

x

8

4

O

8x

4

4 8

13.

y2 4



x2 2

1 8

14. y  x 2, parabola

 1, ellipse

y

y

O

©Glencoe/McGraw-Hill

O

x

233

x

Algebra 2

Chapter 8

15.

x2 4



y2 1

 1, hyperbola

16.

(x  1)2 36



(y  4)2 4

 1,

hyperbola

y

12

y

8

x

O

4 O 8

4

4

8

12x

4

1 9

18. x  (y  4)2  4, parabola

17. y  (x  2)2  4, parabola y

y

x

O

x

O

20. x 2  (y  3)2  36, circle

19. (x  2)2  (y  3)2  9, circle

y

y

4 O 8

4

4

8x

4 8 O

©Glencoe/McGraw-Hill

x

234

Algebra 2

Chapter 8

21.

(x  4)2 32



y2 32

 1, hyperbola 8 6 4 2

22.

(x  1)2 9



y

24.

(y  1)2 25



y 8 6 4 2

x2 4



8642 2 4 6 8

x

(y  1)2 3

x

O

23. x 2  (y  4)2  5, circle

25.

 1, ellipse

26.

(x  1)2 16



x2 9

O 2 4 6 8x

(y  1)2 4

 1, ellipse

y

x O

©Glencoe/McGraw-Hill

 1, hyperbola

y

y

O

 1, ellipse

9 2

y

121086 42 O 2 4 x 2 4 6 8

O

y2

235

x

Algebra 2

Chapter 8

27. y  (x  4)2  7, parabola 12

8

y O

4

28.

(x  2)2 5



(y  1)2 6

 1,

hyperbola

4x

y

4 8

x

O

12 16

29.

(x  3)2 25



(y  1)2 9

 1, ellipse

30. parabolas and hyperbolas

y

O

x

32.

31. hyperbola

y

x

O

33. circle

34. hyperbola

35. parabola

36. ellipse

37. ellipse

38. circle

39. parabola

40. hyperbola

41. b

42. a

43. c

44. 2 intersecting lines

©Glencoe/McGraw-Hill

236

Algebra 2

Chapter 8

45. The plane should be vertical and contain the axis of the double cone.

46. If you point a flashlight at a flat surface, you can make different conic sections by varying the angle at which you point the flashlight. Answers should include the following. • Point the flashlight directly at a ceiling or wall. The light from the flashlight is in the shape of a cone and the ceiling or wall acts as a plane perpendicular to the axis of the cone. • Hold the flashlight close to a wall and point it directly vertically toward the ceiling. A branch of a hyperbola will appear on the wall. In this case, the wall acts as a plane parallel to the axis of the cone.

47. D

48. C

49. 0 e 1, e 1

50.

51.

(x  3)2 9



(y  6)2 4

(y  4)2 36



(x  5)2 16

1

52. (3, 4); (3  25, 4); 6; 4

1

y x

O

54. m12n

53. x12 55.

x7 y4

56. 196 beats per min

57. (2, 6)

58. (3, 2)

59. (0, 2) ©Glencoe/McGraw-Hill

237

Algebra 2

Chapter 8

Lesson 8-7

Solving Quadratic Systems Pages 458–460

1a. (3, 4), (3, 4)

2. The vertex of the parabola is on the ellipse. The parabola opens toward the interior of the ellipse and is narrow enough to intersect the ellipse in two other points. Thus, there are exactly three points of intersection.

y

4x  3y  0 O

x

x 2  y 2  25

1b. (1, 4) y y  2x 2  2

y  5  x2 O

x

3. Sample answer: x 2  y 2  40, y  x 2  x

4. (4, 5)

5. (4, 3), (3, 4)

6. no solution

7. (1, 5), (1, 5)

8.

14 12 10 8 6 4 2 108642 2 4 6

©Glencoe/McGraw-Hill

238

y

O 2 4 6 8 10 x

Algebra 2

Chapter 8

10. (40, 30)

y

9.

O

x

11. (2, 4), (1, 1)

12. a ,

13. (1  217, 1  217),

14. no solution

3 2

9 b, 2

(1, 2)

(1  217, 1  217) 15. ( 25, 25), (25, 25)

16. no solution

17. (5, 0), (4, 6)

18. (0, 3), a

19. (8, 0)

20. (0, 5)

21. no solution

22. (4, 3), (4, 3)

23. (5, 5), (5, 1), (3, 3)

24. (6, 3), (6, 1), (4, 4), (4, 0)

25. a ,  b, (1, 3)

26. (3, 4), (3, 4)

27. 0.5 s

28. Sample answer:

5 3

7 3

11 123 , b 2 4

x2 y2   1, 36 16 x2 (y  2)2   16 4 x2 y2  1 2 16 40  24 25 45  12 25 b , 5 5

29. a

©Glencoe/McGraw-Hill

1,

30. (39.2, 4.4)

239

Algebra 2

Chapter 8

32.

31. No; the comet and Pluto may not be at either point of intersection at the same time.

y

x

O

33.

34.

y

y

x

O

x

O

35.

36.

y

37.

O 8642 2 4 6 8

x

O

y

2 4 6 8x

38. k 3, 2 k 2, or k 3

y

O

8 6 4 2

x

39. none

40. k  2 or k  3

41. none

42. 3 k 2 or 2 k 3

©Glencoe/McGraw-Hill

240

Algebra 2

Chapter 8

43. Systems of equations can be used to represent the locations and/or paths of objects on the screen. Answers should include the following. • y  3x, x 2  y 2  2500 • The y-intercept of the graph of the equation y  3x is 0, so the path of the spaceship contains the origin. • (5 210, 15 210) or about (15.81, 47.43) 45. B

44. A

47. Sample answer:

48. Sample answer:

46. Sample answer: y  x 2, x  (y  2)2

x 2  y 2  36, (x  2)2 16



y2 4

1

49. Sample answer: x 2  y 2  81, x2 4



y2

100

x2 16

x 2  y 2  100,

50. Sample answer:

1

y2 x2  64 16



x2 64

y2 4



1

y2 16

 1,

1

52. (x  2)2  (y  1)2  11, circle

51. impossible

y

O

©Glencoe/McGraw-Hill

241

x

Algebra 2

Chapter 8

53.

(y  3)2 9



x2 4

 1, ellipse

54. (0, 2); (0, 4); y  

y

23 x 3

y

6y 2  2x 2  24

x

O

O

x

55. 7, 0

56. 0, 3

57. 7, 3

58. 7, 5

4 3

3 4

1 2

59. 

60.  ,

61a. 40 61b. two real, irrational

62a. 48 62b. two imaginary

61c. 

210 5

62c. 1 

63. 2  9i 65.

8 5

2i 23 3

64. 29  28i

1 5

 i

66. about 1830 times

67. 6

68. 2

69. 51

70. (5, 3, 7)

71. y  3x  2

72. y   x 

©Glencoe/McGraw-Hill

5 3

242

4 3

Algebra 2

Chapter 8

PQ245-6457F-P09[243-266].qxd 7/31/02 9:54 AM Page 243 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-09:

Chapter 9 Rational Expressions and Equations Lesson 9-1 Multiplying and Dividing Rational Expressions Pages 476–478 4 6

1. Sample answer: ,

4(x  2) 6(x  2)

2. To multiply rational numbers or rational expressions, you multiply the numerators and multiply the denominators. To divide rational numbers or rational expressions, you multiply by the reciprocal of the divisor. In either case, you can reduce your answer by dividing the numerator and the denominator of the results by any common factors.

3. Never; solving the equation using cross products leads to 15  10, which is never true.

4.

9m 4n4

5.

1 ab

6.

3y 2 y4

7.

3c 20b

8.

5 12x

9.

6 5

10.

p5 p1

11. cd 2x

12.

2y(y  2) 3(y  2)

13. D

14.

5c 2b

n2 7m

16. 3x 4y

15.  17.

s 3

18.

5 t1

19.

1 2

20.

y2 3y  1

21.

a1 2a  1

22.

3x 2 2y

Glencoe/McGraw-Hill

243

Algebra 2

Chapter 9

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4bc 27a

23. 

24. f

25. 2p 2

26.

xz 8y

27.

b3 x 2y 2

28. 3

29.

4 3

30.

2 3

31. 1

32.

5(x  3) 2(x  1) 3(r  4) r3

33.

w3 w4

34.

35.

2(a  5) (a  2)(a  2)

36. 

3n m

37. 2p

38.

mn m2  n2

39.

2x  y 2x  y

40. y  1

41.

4 3

42. d  2, 1 or 2

43. a  b or b 45.

44.

6827  m 13,129  a

6827 13,129

46. 2x  1 units 1 a2

47. (2x 2  x  15)m 2

48.

49. A rational expression can be used to express the fraction of a nut mixture that is peanuts. Answers should include the following. • The rational expression 8x is in simplest form

50. C

13  x

because the numerator and the denominator have no common factors.

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8x

• Sample answer: 13  x  y could be used to represent the fraction that is peanuts if x pounds of peanuts and y pounds of cashews were added to the original mixture. 51. A

52. (1, 4), (5, 2)

53. (217, 222)

54. x 

1 3

(y  3)2  1; parabola

y O

x x  13 (y  3)2  1

55.

(x  7)2 (y  2)2 9 1

 1;

56. even; 2

hyperbola 8

y

4

x

O 4 4

8

(x  7) 9

2

12 2



(y  2) 1 1

8

AA

C A BLACK

57. odd; 3

58. even; 0

59. 1, 4

60.  ,

61. 0, 5

62. 4.99  102 s or about 8 min 19 s

63. 

64.

1 1 6 3

1 9

11 24

65. 1

©Glencoe/McGraw-Hill

3 19 , 2 16

66. 1 245

Algebra 2

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4 15

11 16

68. 

67. 1

11 18

69. 

70.

Lesson 9-2

1 6

Adding and Subtracting Rational Epressions Pages 481–484

1. Catalina; you need a common denominator, not a common numerator, to subtract two rational expressions.

2. Sample answer: d 2  d, d  1

3a. Always; since a, b, and c are factors of abc, abc is always a common denominator of

4. 12x 2y 2

1 1 1   . a c b

3b. Sometimes; if a, b, and c have no common factors, then abc is the LCD of 1 1 1   . a c b

3c. Sometimes; if a and b have no common factors and c is a factor of ab, then ab is the 1 1 1 LCD of   . a

b

c

3d. Sometimes; if a and c are factors of b, then b is the 1 1 1 LCD of   . a

b

3e. Always; since

c

1 1 1    a c b

ac ab bc   , the sum abc abc abc bc  ac  ab . always abc

is

6. x(x  2)(x  2)

5. 80ab3c 7.

2  x3 x 2y

©Glencoe/McGraw-Hill

8.

246

42a 2  5b 2 90ab 2

Algebra 2

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37 42m

10.

5d  16 (d  2) 2

11.

3a  10 (a  5)(a  4)

12.

8 5

13.

13x 2  4x  9 2x (x  1)(x  1)

9.

14. 70s 2t 2

units

15. 180x 2yz

16. 420a3b3c 3

17. 36p 3q 4

18. 4(w  3)

19. x 2(x  y)(x  y)

20. (2t  3)(t  1)(t  1)

21. (n  4)(n  3)(n  2)

22.

6  8b ab

23.

31 12v

24.

5  7r r

25.

2x  15y 3y

26.

9x 2  2y 3 12x 2y

27.

25b  7a3 5a 2b 2

28. 

29.

110w  423 90w

30.

13 y8

31.

a3 a4

32.

5m  4 3(m  2)(m  2)

33.

y (y  9) (y  3)(y  3)

34.

7x  38 2(x  7)(x  4)

35.

8d  20 (d  4)(d  4)(d  2)

36.

4h  15 (h  4)(h  5)2

37.

x2  6 (x  2)2(x  3)

38. 0

39.

2y 2  y  4 (y  1)(y  2)

40.

1 b1

42.

2s  1 2s  1

a7 a2

44.

3x  4 2x (x  2)

45. 12 ohms

46.

24 h x

3 20q

41. 1 43.

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47. 49.

24 h x4 2md (d  L)2(d  L) 2 2md 2 (d  L2 ) 2

48. or

50. Sample answer: 1 1 , x1 x2

51. Subtraction of rational expressions can be used to determine the distance between the lens and the film if the focal length of the lens and the distance between the lens and the object are known. Answers should include the following. • To subtract rational expressions, first find a common denominator. Then, write each fraction as an equivalent fraction with the common denominator. Subtract the numerators and place the difference over the common denominator. If possible, reduce the answer. •

1 1 1   q 10 60

48(x  2) h x(x  4)

52. B

could be used

to determine the distance between the lens and the film if the focal length of the lens is 10 cm and the distance between the lens and the object is 60 cm. 54.

53. C

©Glencoe/McGraw-Hill

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4 15xyz 2

Algebra 2

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55.

a(a  2) a1

56.

y 8 x 2  y 2  16 8

8x

O

8 9x 2  y 2  81

57.

58. 2.5 ft

y 2

(y  3)  x  2

x

O

x2 y 4

59.

60.

y

y 15

6

10 2 8

O

5

8x

2

10 5 O

x 6 y  1  20 2

2

5

10x

5

16

10

y2 x2 15  1

49

61.

10 8 6 4 2

25

y

O 2 2 4 6x

6

4 (x  2) (y  5) 1  8 16 25 2

©Glencoe/McGraw-Hill

2

249

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Chapter 9 Practice Quiz 1 Page 484 t2 t3

2.

c 6b 2

3. 

y2 32

4.

7 2

5. (w  4)(3w  4)

6. x  1

1.

7.

4a  1 ab

9.

n  29 (n  6)(n  1)

8.

Lesson 9-3

10.

1 4

Graphing Rational Functions Pages 488–490

1. Sample answer: f(x) 

6ax  20by 15a 2b3

2. Each of the graphs is a straight line passing through (5, 0) and (0, 5). However,

1 (x  5)(x  2)

the graph of f (x) 

(x  1)(x  5) x1

has a hole at (1, 6), and the graph of g(x )  x  5 does not have a hole. 3. x  2 and y  0 are asymptotes of the graph. The y-intercept is 0.5 and there is no x-intercept because y  0 is an asymptote.

4. asymptote: x  2

5. asymptote: x  5; hole: x1

6.

f (x )

O

f (x ) 

©Glencoe/McGraw-Hill

250

x x x 1

Algebra 2

Chapter 9

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7.

8.

f (x ) 4

f (x ) 10

2 6 8

4

2

f (x ) 

4

9.

x 2  25

8x

4

O

2

6 (x  2)(x  3)

4 O

10.

2 8

O

2

10

x

4 ( x  1)2

8x

4

f (x ) 

x 5 x 1

4

O

C

11.

6

f (x ) f (x ) 

4

2

4

f (x )

4

f (x )  x  5

x

C

12. 100 mg

f (x)

O x f(x) 

13.

x 2 x2  x  6

14. y  12, C  1; 0; 0

C 10 6

C

y y  12

8

16 y

2 16 8

O 4

15. y  0 and 0 C 1

16. asymptotes: x  2, hole: x3

17. asymptotes: x  4, x  2

18. asymptotes: x  4, hole: x  3

19. asymptotes: x  1, hole: x5

20. hole: x  4

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21. hole: x  1

22.

f (x ) 1

f (x )  x

x

O

23.

24.

f (x )

f (x ) f (x ) 

1 x2

x

O

x

O

3

f (x )  x

25.

26.

f (x ) 6

f (x ) 

5 x 1

2 8

4

f (x )

x O

4

x

O

8

4

f (x ) 

x x 3

8

27. 8

C

28.

f (x ) f (x ) 

C

f (x ) 

f (x )

5x x 1

3 ( x  2)2

x O

4 8

4

O

4

8x

4

29.

30.

f (x ) f (x ) 

1 ( x  3)2

f (x ) f (x ) 

x 4 x 1

6 2

8

4 O

4

8x

4 O

©Glencoe/McGraw-Hill

x

8

252

Algebra 2

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31.

32.

f (x )

4 8 f(x) 

x

O

f (x ) 

f(x)

4 O

x

4

x 2  36 4 x 6

8

x 1 x 3

12

33.

34.

f(x) f(x) 

f (x )

x2  1 x 1

O x

O

x

f (x ) 

35.

36.

f (x )

f (x ) f (x ) 

O

x

1 ( x  2)( x  3)

37.

38.

f (x ) f (x ) 

x x2  1

x

O

f (x ) 

3 ( x  1)( x  5)

x 1 x2  4

f (x )

f (x )  O

x

O

©Glencoe/McGraw-Hill

6 (x  6)2

253

x

Algebra 2

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39.

40.

f (x ) f (x ) 

f (x )

1 (x  2)2

f (x ) 

64 x 2  16

x

O

x

O

41. The graph is bell-shaped with a horizontal asymptote at f(x)  0.

64 64  a 2 b, x  16 x  16 64 graph of f (x)  2 x  16

42. Since the

2

would be a reflection of the graph of f (x) 

64 x  16 2

over

the x-axis. 43.

44. m1  7; 7; 5

Vf 20 12 4

Vf 

m1  7 m1  7

5

O

16 8 4

8 m1

45. about 0.83 m/s

46. Sample answers: f(x)  f (x)  f (x) 

47.

8

P (x )  12

8

x2 , (x  2)(x  3) 2(x  2) , (x  2)(x  3) 5(x  2) (x  2)(x  3)

48. the part in the first quadrant

P (x )

6x 10 4 x

4 O

4x

4 8

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Algebra 2

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49. It represents her original freethrow percentage of 60%.

50. y  1; This represents 100%, which she cannot achieve because she has already missed 4 free throws.

51. A rational function can be used to determine how much each person owes if the cost of the gift is known and the number of people sharing the cost is s. Answers should include the following. • c

52. A

100 50

s0

c

150 s

O

100 50

50 100 s

50 c  0 100

• Only the portion in the first quadrant is significant in the real world because there cannot be a negative number of people nor a negative amount of money owed for the gift. 53. B 55.

3x  16 (x  3)(x  2)

54.

3m  4 mn

56.

5(w  2) (w  3) 2

58. (2, 0); 113

57. (6, 2); 5 y

y

(x  6)2  ( y  2)2 25 O

O

x

x x 2  y 2  4x  9

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59. $65,892

60. 4  2i

61. 12, 10

62.

63. 4.5

64. 1.4

65. 20

66. 12

Lesson 9-4

7  3 213 2

Direct, Joint, and Inverse Variation Pages 495–498

1a. inverse 1b. direct

2. Both are examples of direct variation. For y  5x, y increases as x increases. For y  5x, y decreases as x increases.

3. Sample answers: wages and hours worked, total cost and number of pounds of apples; distances traveled and amount of gas remaining in the tank, distance of an object and the size it appears

4. inverse; 20

5. direct; 0.5

6. joint;

7. 24

8. 45

9. 8

1 2

10. P  0.43d

11. 25.8 psi

12. about 150 ft

13.

14. direct; 1.5

Depth(ft) Pressure(psi) 0 0 1 0.43 2 0.86 3 1.29 4 1.72

Glencoe/McGraw-Hill

p

256

Algebra 2

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P P  0.43d O

d

15. joint; 5

16. inverse; 18

17. direct; 3

18. inverse; 12

19. direct; 7

20. joint;

21. inverse; 2.5

22. V 

23. V  kt

24. directly; 2

25. 118.5 km

26. 60

27. 20

28. 216

29. 64

30. 25

31. 4

32. 1.25

33. 9.6

34. 12.6

35. 0.83

36. 2

37.

1 3

k p

1 4

1 6

38. 30 mph

39. 100.8 cm3

40. See students’ work.

41. m  20sd

42. joint

43. 1860 lb

44. / 15md

45. joint

46. See students’ work.

47. I 

k d2

48.

I

I  162 d

O

Glencoe/McGraw-Hill

257

d

Algebra 2

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1

0.02P1P2

49. The sound will be heard as 4 intensely.

50. 0.02; C 

51. about 127,572 calls

52. about 601 mi

53. no; d 0

54. Sample answer: If the average student spends $2.50 for lunch in the school cafeteria, write an equation to represent the amount s students will spend for lunch in d days. How much will 30 students spend in a week? a  2.50sd; $375

55. A direct variation can be used to determine the total cost when the cost per unit is known. Answers should include the following. • Since the total cost T is the cost per unit u times the number of units n or C  un, the relationship is a direct variation. In this equation u is the constant of variation. • Sample answer: The school store sells pencils for 20¢ each. John wants to buy 5 pencils. What is the total cost of the pencils? ($1.00)

56. D

57. C

58. asymptote: x  1; hole x  1

59. asymptotes: x  4, x  3

60. hole: x  3 t 2  2t  2 (t  2)(t  2)

61.

x yx

62.

63.

m (m  1) m5

64. 9.3  107

65. 0.4; 1.2

66. 3; 7

3 5

67.  ; 3

68. C

69. A

70. S

©Glencoe/McGraw-Hill

d2

258

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71. P

72. A

73. C

Chapter 9 Practice Quiz 2 Page 498 1.

2.

f (x )

f (x ) O

1 f (x )  xx  4

x

x

O

f (x ) 

3. 49

2 x  6x  9 2

4. 4.4

5. 112

Lesson 9-5 Classes of Functions Pages 501–504 2. constant (y  1), direct variation (y  2x), identity (y  x)

1. Sample answer: P

O

d

This graph is a rational function. It has an asymptote at x  1. 3. The equation is a greatest integer function. The graph looks like a series of steps.

4. greatest integer

5. inverse variation or rational

6. constant

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Algebra 2

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7. c

8. b

9. identity or direct variation

10. quadratic

y

y

y  x 2  2

x

O

yx x

O

12. A  r 2; quadratic; the graph is a parabola

11. absolute value y

y x2

O

x

13. absolute value

14. square root

15. rational

16. direct variation

17. quadratic

18. constant

19. b

20. e

21. g

22. a

23. constant

24. direct variation y

y

y  2.5x x

O

O

x

y  1.5

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25. square root

26. inverse variation or rational

y

y y  4x

y  兹9x

x

O

x

O

AA

C A BLACK

27. rational

28. greatest integer y

y

2 yx 1

x1

y  3[x ]

x

O

x

O

29. absolute value

30. quadratic y

y

y  2x O

y  2x 2 x

O

x

31. C  4.5 m

32. direct variation

33. a line slanting to the right and passing through the origin

34. similar to a parabola

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35.

36. The graph is similar to the graph of the greatest integer function because both graphs look like a series of steps. In the graph of the postage rates, the solid dots are on the right and the circles are on the left. However, in the greatest integer function, the circles are on the right and the solid dots are on the left.

y

Cost (cents)

160 120 80 40 x

0 2

4 6 Ounces

8

10

37a. absolute value 37b. quadratic 37c. greatest integer 37d. square root

38. A graph of the function that relates a person’s weight on Earth with his or her weight on a different planet can be used to determine a person’s weight on the other planet by finding the point on the graph that corresponds with the weight on Earth and determining the value on the other planet’s axis. Answers should include the following. • The graph comparing weight on Earth and Mars represents a direct variation function because it is a straight line passing through the origin and is neither horizontal nor vertical. • The equation V  0.9E compares a person’s weight on Earth with his or her weight on Venus. V

Venus

80 60 40 20

E

0 20

©Glencoe/McGraw-Hill

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40 60 Earth

80

Algebra 2

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39. C

40. D

41. 22

42.

f (x ) 3 f (x )  x  2

x

O

43.

44.

f (x )

f (x ) 2 f (x )  x  5x  4

x4

x

O

f (x )  (

8 x  1)(x  3)

46. a3 , 1b ; a2 , 1b;

45. (8, 1); a8,  b ; x  8; y 14 12 10 8 6 4 2 2 2

7 8 1 1 1 ; up; 8 2

x

O

1 4

y  1; x

unit

1 4 1  4 ; 4

right; 4 units

y

y

1

1

x  4 y2  2 y  3 1( y  1)  (x  8)2 2

O 2 4 6

©Glencoe/McGraw-Hill

10 12

O

x

x

263

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47.

48. c

(5, 4); a5 , 4b ; y  4; 3 4

25 23 54 d 66 26 57

1 4

x  4 ; right; 3 units y x

O

3x  y 2  8y  31

49. impossible

50. (7, 5)

51. a , 2b

52. (2, 2)

53. 1

54. 12

1 3

17 6

55. 

56. 60a3b 2c 2

57. 45x 3y 3

58. 15(d  2)

59. 3(x  y)(x  y)

60. (a  3)(a  1)(a  2)

61. (t  5)(t  6)(2t  1)

Lesson 9-6

Solving Rational Equations and Inequalities Pages 509–511 2. 2(x  4); 4

1. Sample answer: 1 5



2 a2

1

3. Jeff; when Dustin multiplied by 3a, he forgot to multiply the 2 by 3a.

4. 3

5. 2, 6

6.

7. 6, 2

8. 2 c 2

©Glencoe/McGraw-Hill

264

2 3

Algebra 2

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2 9

1 6

9. v 0 or v  1

10. 2 h 4 3

11. 2

12. 

13. 6, 1

14. 3, 2

15. 1 a 0

16. 1 m 1

17. 11

18. 3

19. t 0 or t  3

20. 0 b 1

21. 0 y 2

22. p 0 or p  2

23. 14

24.

25. 

26. 

27. 7

28.

7 3

30.

1  2145 4

29.

3  3 22 2

3 2

31. 32

32. 2 or 4

33. band, 80 members; chorale, 50 members

34. 4.8 cm/g

35. 24 cm

36. 15 km/h

37. 5 mL

38. 5

39. 6.15

40.

41. If something has a general fee and cost per unit, rational equations can be used to determine how many units a person must buy in order for the actual unit price to be a given number. Answers should include the following.

42. B

• To solve

500  5x x

1 2

b bc  1

 6,

multiply each side of the equation by x to eliminate the rational expression. ©Glencoe/McGraw-Hill

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Then subtract 5x from each side. Therefore, 500  x. A person would need to make 500 minutes of long distance calls to make the actual unit price 6¢. • Since the cost is 5¢ per minute plus $5.00 per month, the actual cost per minute could never be 5¢ or less. 44. quadratic

43. C

y

y  2x 2  1 x

O

46. direct variation

45. square root

y

y

O

y  0.8x

y  2兹x O

x

47. 36

48. 33.75

49. 22130

50. 225

52. 5x 0 x 11 or x  36

51. 2137 53. 5x 0 0 x 46

©Glencoe/McGraw-Hill

x

54. e b ` 1 b 2 f 1 2

266

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Chapter 10 Esponential and Logarithmic Relations Lesson 10-1 Exponential Functions Pages 527–530 2a. 2b. 2c. 2d.

1. Sample answer: 0.8

quadratic exponential linear exponential

4. a

3. c

6. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

5. b

y

y  3(4)x

O

7. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

x

8. growth

y

( 13 )x

y2

O

x

10. growth

9. decay 1 x 2

11. y  3a b

12. y  18132 x

13. 2227 or 427

14. a4

15. 3322 or 2722

16. 9

17. x  0

18. 2

19. y  65,000(6.20)x

20. 22,890,495,000

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21. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

22. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

y

y

y  5(2)x y  2(3)x x

O

x

O

23. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

24. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

y

y

y4

)x

y  0.5(4

x

O

x

O

25. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

x

( 13 )

26. D  {x 0 x is all real numbers.}, R  {y 0 y  0}

y

y

x O

O

x

y  2.5(5)x y

( 15 )x

27. growth

28. growth

29. decay

30. growth

31. decay

32. decay 1 x 4

33. y  2 a b

34. y  3(5)x

35. y  7(3)x

36. y  5 a b

37. y  0.2(4)x

38. y  0.3(2)x

©Glencoe/McGraw-Hill

1 x 3

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39. 54 or 625

40. x115

41. 7412

42. y 2 13

43. n 2

44. 25

45. n  5

46.

47. 1

48. n  2 8 3

2 3

49. 

50. 0

51. n  3

52.

53. 3

54. p 2

55. 10

56. 3, 5

57. y  100(6.32)x

58. about 1,008,290

59. y  3.93(1.35)x

60. 9.67 million; 17.62 million; 32.12 million; These answers are in close agreement with the actual populations in those years.

61. 2144.97 million; 281.42 million; No, the growth rate has slowed considerably. The population in 2000 was much smaller than the equation predicts it would be.

62. Exponential; the base, 1  , n is fixed, but the exponent, nt, is variable since the time t can vary.

63. A(t )  1000(1.01)4t 65. s . 4x

64. $2216.72

67. Sometimes; true when b  1, but false when b  1.

68. The number of teams y that could compete in a tournament with x rounds can be expressed as y  2x. The 2 teams that make it to the final round got there as a result of winning games played with 2 other teams, for a total of 2 2  22 or 4 games played in the previous rounds. Answers should include the following.

©Glencoe/McGraw-Hill

5 3

r

66. 1.5 three-year periods or 4.5 yr

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• Rewrite 128 as a power of 2, 27. Substitute 27 for y in the equation y  2x. Then, using the Property of Equality for Exponents, x must be 7. Therefore, 128 teams would need to play 7 rounds of tournament play. • Sample answer: 52 would be an inappropriate number of teams to play in this type of tournament because 52 is not a power of 2. 69. A

70. 780.25

71.

72.

[5, 5] scl: 1 by [1, 9] scl: 1

[5, 5] scl: 1 by [1, 9] scl: 1

The graphs have the same shape. The graph of y  3x1 is the graph of y  3x translated one unit to the left. The asymptote for the graph of y  3x and for y  3x1 is the line y  0. The graphs have the same domain, all real numbers, and range, y  0. The y-intercept of the graph of y  3x is 1 and for the graph of y  3x1 is 3.

The graphs have the same shape. The graph of y  2x  3 is the graph of y  2x translated three units up. The asymptote for the graph of y  2x is the line y  0 and for y  2x  3 is the line y  3. The graphs have the same domain, all real numbers, but the range of y  2x is y  0 and the range of y  2x  3 is y  3. The y-intercept of the graph of y  2x is 1 and for the graph of y  2x  3 is 4.

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73.

74.

[5, 5] scl: 1 by [1, 9] scl: 1

[5, 5] scl: 1 by [3, 7] scl: 1

The graphs have the same shape. The graph of

The graphs have the same shape. The graph of y

1 x2 a b 5

x

y  a b 1 is the graph of 1 4

is the graph of

x

y  a b translated two units

y  a b translated one

to the right. The asymptote

unit down. The asymptote

1 5

x

1 4

1 5

1 5

1 4

the line y  0 and

x2

for y  a b

is the line

for the graph of y 

y  0. The graphs have the same domain, all real numbers, and range, y  0. The y-intercept of the graph of y 

1 x a b 5

graph of y 

1 x a b 4

1

is the line y  1. The graphs have the same domain, all real numbers, but the range of y 

is 1 and for the 1 x2 a b 5

x

for the graph of y  a b is

x

for the graph of y  a b and

1 x a b 4 x

is y  0 and of y  a b  1 1 4

is 25.

is y  1. The y-intercept x

of the graph of y  a b is 1 1 4

and for the graph of y 75. For h  0, the graph of y  2x is translated 0 h 0 units to the right. For h  0, the graph of y  2x is translated |h| units to the left. For k  0, the graph of y  2x is translated 0k 0 units up. For k  0, the graph of y  2x is translated 0k 0 units down. ©Glencoe/McGraw-Hill

1 x a b 4

 1 is 0.

76. 1, 15

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13 3

77. 1, 6

78.  , 3

79. 0  x  3 or x  6

80. square root

81. greatest integer

82. constant y y8

O

1 0 R 0 1

83. B 85.

3 1 B 51 11

x

84. does not exist 6 R 5

86. about 23.94 cm 88. g [h(x)]  x 2  6x  9; h [g(x)]  x 2  3

87. g [h(x)]  2x  6; h [g(x)]  2x  11 89. g [h(x)]  2x  2; h [g(x)]  2x  11

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Logarithms and Logarithmic Functions Pages 535–538

1. Sample answer: x  5y and y  log5 x

2. They are inverses.

3. Scott; the value of a logarithmic equation, 9, is the exponent of the equivalent exponential equation, and the base of the logarithmic expression, 3, is the base of the exponential equation. Thus x  39 or 19,683.

4. log5 625  4

5. log7

1 49

6. 34  81

 2

1

7. 362  6

8. 4

9. 3

10. 21

11. 1

12. 27

13. 1000

14.

15.

1 , 2

1 2

x5

16. x  6

1

17. 3

18. 1013

19. 107.5

20. 105.5 or about 316,228 times

21. log8 512  3

22. log3 27  3

23. log5

1 125

24. log 31 9  2

 3

25. log100 10 

1 2

26. log2401 7  28. 132  169

27. 53  125 29. 41 

1 4

30. 1002  1

1 2 5

31. 83  4

32. a b

33. 4

34. 2

2

©Glencoe/McGraw-Hill

1 4

273

1 10

 25

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1 2

36.

5 2

37. 5

38. 4

39. 7

40. 45

41. n  5

42. 3x  2

43. 3

44. 2x

45. 1018.8

46. 1010.67

47. 81

48. c  256

49. 0  y  8

50. 125

51. 7

52. 0  p  1

53. x 24

54. 3

55. 4

56. 11

57. 2

58. 25

59. 5

60. y 3

61. a  3

62. 8 ?

63. log5 25  2 log5 5 2 ?

log5 5  2 log5 5 ?

2  2(1)

2  2✓

1

64.

Original equation

?

log16 2  log2 16  1

25  5 and 5  51 2

1

?

log16 164  log2 24  1

Inverse Prop. of Exp. and Logarithms Simplify.

1 (4) 4

Original equation 1

2  164 and 16  24

?

 1 Inverse Prop. of Exp. and Logarithms

1  1✓

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66a.

65. ?

log7 [log3 (log2 8)]  0

Original equation

?

log7 [log3 (log2 23)]  0

y

8  23

log7 (log3 3)  0

Inverse Prop. of Exp. and Logarithms

?

log7 (log3 31)  0

y  log 1 x 2

66b. The graphs are reflections of each other over the line y  x.

3  31

?

log7 1  0

x

( 12 )

x

O

?

?

y

Inverse Prop. of Exp. and Logarithms

log7 70  0 0  0✓

1  70 Inverse Prop. of Exp. and Logarithms

68. 103 or 1000 times as great

67a. y

y  log2(x  2)

y  log2x  3 y  log2(x  1) O

x

y  log2x  4

67b. The graph of y  log2 x  3 is the graph of y  log2 x translated 3 units up. The graph of y  log2 x  4 is the graph of y  log2 x translated 4 units down. The graph of log2 (x  1) is the graph of y  log2 x translated 1 unit to the right. The graph of log2 (x  2) is the graph of y  log2 x translated 2 units to the left. 69. 101.4 or about 25 times as great

©Glencoe/McGraw-Hill

70. 101.7 or about 50 times 275

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71. 2 and 3; Sample answer: 5 is between 22 and 23.

72. All powers of 1 are 1, so the inverse of y  1x is not a function.

73. A logarithmic scale illustrates that values next to each other vary by a factor of 10. Answers should include the following. • Pin drop: 1 100; Whisper: 1 102; Normal conversation: 1 106; Kitchen noise: 1 1010; Jet engine: 1 1012 •

74. B

Pin drop

Whisper (4 feet)

Normal conversation

2  10 11

0

4  10 11

Kitchen noise

6  10 11

Jet engine

8  10 11 1  10 12

• On the scale shown above, the sound of a pin drop and the sound of normal conversation appear not to differ by much at all, when in fact they do differ in terms of the loudness we perceive. The first scale shows this difference more clearly. 75. D

76. x 216

77. b12

78.

79. 3,

7 3

14 5

80.

81.

5 273 4

82.

83.

6x  58 (x  3)(x  3)(x  7)

84. $2400, CD; $1600, savings

43 30y

85. x10

86. y 24

87. 8a6b 3

88. an6

89.

x3 y 2z 3

©Glencoe/McGraw-Hill

90. 1

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Chapter 10 Practice Quiz 1 Page–538 1. growth

2. y  2(4)x

3. log4 4096  6

4. 92  27

3

5.

4 3

6. 15

7.

3 5

8. n  1

9. x  26

10. 3

Lesson 10-3

Properties of Logarithms Pages 544–546

1. properties of exponents

2. Sample answer: 2log3 x  log3 5; log3 5x 2

3. Umeko; Clemente incorrectly applied the product and quotient properties of logarithms. log7 6  log7 3  log7 (6 3) or log7 18 Product Property of

4. 1.1402

Logarithms

log7 18  log7 2  log7 (18  2) or log7 9 Quotient Prop. of Logarithms

5. 2.6310

6. 0.3690

7. 6

8. 2

9. 3

10. 4

11. pH  6.1  log10

B C

12. 20:1

13. 1.3652

14. 1.2921

15. 0.2519

16. 0.2519

17. 2.4307

18. 2.1133

19. 0.4307

20. 0.0655

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21. 2

22. 3

23. 4

24. 2

25. 14

26. 12

27. 2

28. 4

29.

30. 6

31. 10

32. 12

33.

x3 4

34.

35. False; log2 (22  23)  log2 12, log2 22  log2 23  2  3 or 5, and log2 12 Z 5, since 25 Z 12.

1 1x 2

 12

36. ? n logb x  m logb x  (n  m)logb x ? logb x n  logb x m  (n  m)logb x

Power Prop. of Logarithms ?

logb (x n  x m)  (n  m)logb x Product Prop. of Logarithms ?

logb (x nm)  (n  m)logb x Product of Powers Prop.

(n  m)logb x  (n  m)logb ✓ Power Prop. of Logarithms

C2 C1

37. 2

38. E  1.4 log

39. about 0.4214 kilocalories per gram

40. about 0.8429 kilocalories per gram

41. 3

42. 3

43. About 95 decibels; L  10 log10 R, where L is the loudness of the sound in decibels and R is the relative intensity of the sound. Since the crowd increased by a factor of 3, we assume that the intensity also increases by a factor of 3. Thus, we need to find the loudness of 3R.

44. 5

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L  10 log10 3R L  10 (log10 3  log10 R ) L  10 log103  10 log10 R L  10(0.4771)  90 L  4.771  90 or about 95 45. 7.5

46. about 22

47. Let b x  m and b y  n. Then logb m  x and logb n  y.

48. Since logarithms are exponents, the properties of logarithms are similar to the properties of exponents. The Product Property states that to multiply two powers that have the same base, add the exponents. Similarly, the logarithm of a product is the sum of the logarithms of its factors. The Quotient Property states that to divide two powers that have the same base, subtract their exponents. Similarly, the logarithm of a quotient is the difference of the logarithms of the numerator and the denominator. The Power Property states that to find the power of a power, multiply the exponents. Similarly, the logarithm of a power is the product of the logarithm and the exponent. Answers should include the following. • Quotient Property:

bx by



b xy 

m n m n

Quotient Prop.

m Prop. of n Equality for Logarithmic Equations m logb Inverse n Prop. of

logb b x y  logb

xy

Exp. and Logarithms

logb m  logb n  logb

m Replace x n with log m b and y with logbn.

log2

32 a b 8

 log2

25 a 3b 2

 log2 2(53)  5  3 or 2

©Glencoe/McGraw-Hill

279

Replace 32 with 25 and 8 with 23. Quotient of Powers Inverse Prop. of Exp. and Logarithms

Algebra 2

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log2 32  log2 8  log2 25  log2 23 Replace 32 with 25 and 8 with 23.

 5  3 or 2 Inverse Prop. of Exp. and Logarithms

So, log2 a

32 b 8

 log2 32  log2 8

Power Property: log3 94  log3 (32)4

Replace 9 with 32.

 log3 3(24)  2  4 or 8

Power of a Power Inverse Prop. of Exp. and Logarithms

4 log3 9  (log3 9)  4

Comm ( )

 (log3 32)  4  2  4 or 8

Replace 9 with 32. Inverse Prop. of Exp. and Logarithms

So, log3 94  4 log3 9. • The Product of Powers Property and Product Property of Logarithms both involve the addition of exponents, since logarithms are exponents. 50. Let b x  m, then logb m  x. (b x)p  m p b xp  m p Product of Powers logb b xp  logb m p Prop. of Equality

49. A

for Logarithmic Equations

xp  logb m p plogb m  logb m p 51. 4

52. 3

53. 2x

54. 6

55. 8

56. d  4

57. odd; 3

58. even; 4

©Glencoe/McGraw-Hill

280

Inverse Prop. of Exp. and Logarithms Replace x with logb m.

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59.

3b a

60. 2

61.

5 3x

62. 3.06 s 64. 5

63. 1 65. x 

3 4

5 3

66.   x  2

Lesson 10-4 Common Logarithms Pages 549–551 1. 10; common logarithms

2. Sample answer: 5x  2; x  0.4307

3. A calculator is not programmed to find base 2 logarithms.

4. 0.6021

5. 1.3617

6. 0.3010

8. {n 0 n  0.4907}

7. 1.7325

10. 1.1615

9. 4.9824

12. {p 0 p  4.8188}

11. 11.5665 13.

log 5 ; log 7

0.8271

14.

15.

log 9 ; log 2

3.1699

16. at most 0.00003 mole per liter

log 42 ; log 3

3.4022

17. 0.6990

18. 1.0792

19. 0.8573

20. 0.3617

21. 0.0969

22. 1.5229

23. 11

24. 2.2

25. 2.1

26. 3.5

27. {x 0 x 2.0860}

28. 2.4550

29. {a 0 a  1.1590}

30. 0.5537

31. 0.4341

32. 4.8362

33. 4.7820

34. 8.0086

©Glencoe/McGraw-Hill

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36. 2.6281

35. 1.1909

37. {n 0 n  1.0178}

38. 1.0890

39. 3.7162

40. {p 0 p  1.9803}

41. 0.5873

42. 4.7095

43. 7.6377

44. 2.7674

45.

log 13 log 2

47.

log 3 log 7

49.

2log 1.6 log 4

 3.7004

 0.5646  0.6781

46.

log 20 log 5

48.

log 8 log 3

50.

0.5 log 5 log 6

 1.8614

 1.8928  0.4491

51. between 0.000000001 and 0.000001 mole per liter

52. 8

53. Sirius

54. Sirius: 1.45, Vega: 0.58

55. Vega

56a. 3;

1 3 3 2 56b. ; 2 3

56c. conjecture: loga b 

1 ; logba

proof: ?

1 log b a

?

1 logb a 1 logb a

loga b  logb b logb a 1 logb a



Change of Base Formula



Inverse Prop. of Exponents and Logarithms

58. about 11.64 yr or 11 yr, 8 mo

57. about 3.75 yr or 3 yr 9 mo

©Glencoe/McGraw-Hill



Original statement

282

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59. Comparisons between substances of different acidities are more easily distinguished on a logarithmic scale. Answers should include the following. • Sample answer: Tomatoes: 6.3 105 mole per liter Milk: 3.98 107 mole per liter Eggs: 1.58 108 mole per liter • Those measurements correspond to pH measurements of 5 and 4, indicating a weak acid and a stronger acid. On the logarithmic scale we can see the difference in these acids, whereas on a normal scale, these hydrogen ion concentrations would appear nearly the same. For someone who has to watch the acidity of the foods they eat, this could be the difference between an enjoyable meal and heartburn.

60. A

61. C

62. 1.4248

63. 1.6938

64. 1.8416

65. 64

66. z 

67. 62

68. 22

69. (d  2)(3d  4)

70. (7p  3)(6q  5)

71. prime

72. 2x  3

73. 32  x

74. 53  125

75. log5 45  x

76. log7 x  3

1 64

77. logb x  y ©Glencoe/McGraw-Hill

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Base e and Natural Logarithms Pages 557–559

1. the number e

2. e x  8

3. Elsu; Colby tried to write each side as a power of 10. Since the base of the natural logarithmic function is e, he should have written each side as a power of e; 10ln 4x Z 4x.

4. 403.4288

5. 0.0334

6. 0.1823

7. 2.3026

8. x  ln 4

9. e0  1

10. 3

11. 5x

12. x  3.4012

13. 1.0986

14. 0.8047

15. 0  x  403.4288

16. 2.4630

17. 90.0171

18. h  26200 ln

19. about 15,066 ft

20. 54.5982

21. 148.4132

22. 0.3012

23. 1.6487

24. 1.0986

25. 2.3026

26. 1.6901

27. 3.5066

28. $183.21

29. about 49.5 cm

30. x  ln 5

31. 2  ln 6x

32. e1  e

33. e x  5.2

34. 0.2

35. y

36. 4x

37. 45

38. 0.2877

39. 0.6931

40. x  1.5041

41. x  0.4700

42. 0.2747

43. 0.5973

44. x 0.6438

45. x 0.9730

46. 27.2991

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47. 49.4711

48. 1.7183

49. 14.3891

50. 232.9197

51. 45.0086

52. 2, 6

53. 1

54. about 19.8 yr

55. t 

100 ln 2 r

56. 100 ln 2  70

57. t 

110 r

58. about 7.33 billion

59. about 55 yr

60. about 32 students

61. about 21 min

62. always; log x log y

?



In x In y

Original statement

log x logx ? log e  log y logy log e

63. The number e is used in the formula for continuously compounded interest, A  Pe rt. Although no banks actually pay interest compounded continually, the equation is so accurate in computing the amount of money for quarterly compounding or daily compounding, that it is often used for this purpose. Answers should include the following.

©Glencoe/McGraw-Hill

log x log y



?

log x log e

log x log y



?

log x log y

Change of Base Formula



log e log y

Multiply log x by the log e reciprocal of log y . log e Simplify.

64. B

285

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• If you know the annual interest rate r and the principal P, the value of the account after t years is calculated by multiplying P times e raised to the r times t power. Use a calculator to find the value of e rt. • If you know the value A you wish the account to achieve, the principal P, and the annual interest rate r, the time t needed to achieve this value is found by first taking the natural logarithm of A minus the natural logarithm of P. Then, divide this quantity by r. 65. 1946, 1981, 2015; It takes between 34 and 35 years for the population to double. 67.

log 0.047 log 6

 1.7065

66.

log 68 log 4

 3.0437

68.

log 23 log 50

 0.8015

69. 5

70. 4

71. inverse; 4

72. joint; 1

73. direct; 7

74. x 

75. 3.32

76. 1.54

77. 1.43

78. 323.49

79. 13.43

80. 9.32

©Glencoe/McGraw-Hill

286

1 2 y 20

5

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Chapter 10 Practice Quiz 2 Page 559 1.

log 5 ; log 4

2. e 2  3x

1.1610

4. x  5.3219

3. 3 5. 1.3863

Lesson 10-6

Exponential Growth and Decay Pages 563–565

1. y  a(1  r)t, where r  0 represents exponential growth, and r  0 represents exponential decay.

2. Take the common logarithm of each side, use the Power Property to write log (1  r)t as t log(1  r), and then divide each side by the quantity log(1  r).

3. Sample answer: money in a bank

4. Decay; the exponent is negative.

5. about 33.5 watts

6. about 402 days

7. y  212,000e0.025t

8. about 349,529 people

9. C

10. $1600

11. at most $108,484.93

12. about 8.1 days

13. No; the bone is only about 21,000 years old, and dinosaurs died out 63,000,000 years ago.

14. more than 44,000 years ago

15. about 0.0347

16. y  ae0.0347t

17. $12,565 billion

18. about 2025

19. after the year 2182

20. 4.7%

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21. Never; theoretically, the amount left will always be half of the previous amount.

22. Answers should include the following. • Find the absolute value of the difference between the price of the car for two consecutive years. Then divide this difference by the price of the car for the earlier year. • Find 1 minus the rate of decrease in the value of the car as a decimal. Raise this value to the number of years it has been since the car was purchased, and then multiply by the original value of the car.

23. about 19.5 yr

24. D

25. ln y  3

26. ln 29  4n  2

27. 4x 2  e8

28. 1.5323

29. p  3.3219

30. 9

31.

0.5 (0.08 p) 6

33.

p 150



0.5 (0.08 p) 4

32.

p 60

34. hyperbola

35. ellipse

36. parabola

37. circle

38. 2.06 108

39. 8 107

40. about 38.8%

©Glencoe/McGraw-Hill

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Chapter 11 Sequences and Series Lesson 11-1 Arithmetic Sequences Pages 580–582 1. The differences between the terms are not constant.

2. 95

3. Sample answer: 1, 4, 9, 14, . . .

4. 24, 28, 32, 36

5. 3, 5, 7, 9

6. 5, 8, 11, 14, 17

7. 14, 12, 10, 8, 6

8. 43

9. 112

10. 79

11. 15

12. an  11n  37

13. 56, 68, 80

14. $12,000

15. 30, 37, 44, 51

16. 10, 3, 4, 11

17. 6, 10, 14, 18

18. 1, 4, 7, 10

19.

7 , 3

3,

11 13 , 3 3

20.

12 , 5

8 6 5 5

2, ,

21. 5.5, 5.1, 4.7, 4.3

22. 8.8, 11.3, 13.8, 16.3

23. 2, 15, 28, 41, 54

24. 41, 46, 51, 56, 61

25. 6, 2, 2, 6, 10

26. 12, 9, 6, 3, 0

27.

4 , 3

2 1 3 3

1, , , 0

28.

5 , 8

1,

11 7 17 , , 8 4 8

29. 28

30. 49

31. 94

32. 175

33. 335

34. 340

35.

26 3

25 2

36. 

37. 27

38. 47

39. 61

40. 173

41. 37.5 in.

42. 304 ft

43. 30th

44. 19th

45. 82nd

46. an  9n  2

47. an  7n  25

48. an  2n  1

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49. 13, 17, 21

50. pn  4n  3

51. Yes; it corresponds to n  100.

52. 70, 85, 100

53. 4, 2

54. 5, 2, 1, 4

55. 7, 11, 15, 19, 23

56. z  2y  x

57. Arithmetic sequences can be used to model the numbers of shingles in the rows on a section of roof. Answers should include the following. • One additional shingle is needed in each successive row. • One method is to successively add 1 to the terms of the sequence: a8  9  1 or 10, a9  10  1 or 11, a10  11  1 or 12, a11  12  1 or 13, a12  13  1 or 14, a13  14  1 or 15, a14  15  1 or 16, a15  16  1 or 17. Another method is to use the formula for the nth term: a15  3  (15  1)1 or 17.

58. B

59. B

60. about 26.7%

61. 0.4055

62. 0.4621

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63. 146.4132

64. 15

65. 2, 5, 8, 11

66. 5, 4, 3, 2

67. 11, 15, 19, 23, 27

Lesson 11-2 Arithmetic Series Pages 586–587 2. Sample answer: 0  1  2  34

1. In a series, the terms are added. In a sequence, they are not. 4

3. Sample answer: a (3n  4)

4. 1300

5. 230

6. 1932

7. 552

8. 800

n1

9. 260

10. 63

11. 95

12. 11, 20, 29

13. 6, 0, 6

14. 28

15. 344

16. 663

17. 1501

18. 2646

19. 9

20. 88

21. 104

22. 182

23. 714

24. 225

25. 14

26. 

27. 10 rows

28. 8 days

29. 721

30. 735

31. 162

32. 204

33. 108

34. 35

35. 195

36. 510

37. 315,150

38. 24,300

39. 1,001,000

40. 166,833

41. 17, 26, 35

42. 13, 8, 3

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245 6

291

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43. 12, 9, 6

44. 13, 18, 23

45. 265 ft

46. True; for any series, 2a1  2a2  2a3  p  2an  2(a1  a2  a3  p  an).

47. False; for example, 7  10  13  16  46, but 7  10  13  16  19  22  25  28  140.

48. Arithmetic series can be used to find the seating capacity of an amphitheater. Answers should include the following. • The sequence represents the numbers of seats in the rows. The sum of the first n terms of the series is the seating capacity of the first n rows. • One method is to write out the terms and add them: 18  22  26  30  34  38  42  46  50  54  360. Another method is to use the formula n Sn  [2a1  (n  1)d ]: S10

2 10  2

[2(18) 

(10  1)4] or 360. 49. C

50. C

51. 5555

52. 3649

53. 6683

54. 111

55. 135

56. about 3.82 days 16 3

9 2

58. 

57.  59.

3  289 2

60. 23

61. 26 221

62. 2 22

63. 16

64. 54

65.

2 27

©Glencoe/McGraw-Hill

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Lesson 11-3 Geometric Sequences Pages 590–592 1a. Geometric; the terms have a common ratio of 2. 1b. Arithmetic; the terms have a common difference of 3.

2. Sample answer:

3. Marika; Lori divided in the wrong order when finding r.

4. 67.5, 101.25

5. 2, 4

6. 2, 6, 18, 54, 162

7.

2 4 8 , 3 9 27

1, , ,

15 64

8. 56

9. 4

10. an  4  2n1

11. 3, 9

12. A

13. 15, 5

14. 192, 256

15. 54, 81

16. 48, 32

17.

p

20 40 , 27 81

18.

125 625 , 24 48

19. 2.16, 2.592

20. 21.875, 54.6875

21. 2, 6, 18, 54, 162

22. 1, 4, 16, 64, 256

23. 243, 81, 27, 9, 3

24. 576, 288, 144, 72, 36

25.

3 16

26. 2592

27. 729

28. 1024

29. 243

30.

31. 1

32. 192

33. 78,125

34. 2

35. 8748

36.

37. 655.36 lb

38. $46,794.34 n1

39. an 

5 72 n1

40. an  64 a b

1 36 a b 3

1 4

42. an  4(3)n 1

41. an  2(5)n 1

©Glencoe/McGraw-Hill

1 4

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43. 18, 36, 72

44. 12, 36, 108

45. 16, 8, 4, 2

46. 6, 12, 24, 48

47. 8 days

48. 5 mg

49. False; the sequence 1, 4, 9, 16, p, for example, is neither arithmetic nor geometric.

50. False, the sequence 1, 1, 1, 1, p, for example, is arithmetic (d  0) and geometric (r  1).

51. The heights of the bounces of a ball and the heights from which a bouncing ball falls each form geometric sequences. Answers should include the following. • 3, 1.8, 1.08, 0.648, 0.3888 • The common ratios are the same, but the first terms are different. The sequence of heights from which the ball falls is the sequence of heights of the bounces with the term 3 inserted at the beginning.

52. A

53. C

54. 632.5

55. 203

56. 19, 23

57. 12, 16, 20

58. 5 22  3 210 units

59. 127

60.

61.

63 32

61 81

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Chapter 11 Practice Quiz 1 Page 592 11 2

1. 46

2.

3. 187

4. 816

5. 1

Lesson 11-4 Geometric Series Pages 596–598 2. The polynomial is a geometric series with first term 1, common ratio x, and 4 terms. The sum is

1. Sample answer: 421

1 2

1(1  x 4) x4  1  . 1x x1

4. 732

3. Sample answer: The first term is a1  2. Divide the second term by the first to find that the common ratio is r  6. Therefore, the nth term of the series is given by 2  6n1. There are five terms, so the series can be 5

written as a 2  6n1. n1

5. 39,063

6. 81,915

7. 165

8.

9. 129

10.

11.

1093 9

1330 9 31 4

12. 3

13. 3

14. 93 in. or 7 ft 9 in.

15. 728

16. 765

17. 1111

18. 300

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19. 244

20. 1,328,600

21. 2101

22. 1441

23.

728 3

24.

215 4

25. 1040.984

26. 7.96875

27. 6564

28. 118,096

29. 1,747,625

30. $10,737,418.23

31. 3641

32. 206,668

33.

182 9

5461 16

34. 

36. 364

35. 2555 37.

387 4

38.

58,975 256

39. 3,145,725

40. 86,093,440

41. 243

42. 1024

43. 2

44. 6

45. 80

46. 8

47. about 7.13 in.

48. If the first term and common ratio of a geometric series are integers, then all the terms of the series are integers. Therefore, the sum of the series is an integer.

49. If the number of people that each person sends the joke to is constant, then the total number of people who have seen the joke is the sum of a geometric series. Answers should include the following. • The common ratio would change from 3 to 4. • Increase the number of days the joke circulates so that it is inconvenient to find and add all the terms of the series.

50. A

©Glencoe/McGraw-Hill

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51. C

52. 1,048,575

53. 3.99987793

54. 6.24999936 9

1 3 4 2

27

81

55.  , , 9

56. 3,  ,  ,  2 4 8

57. 232

58. 192

59. Drive-In Movie Screens

60. Sample answer using (1, 826) and (3, 750): y  38x  864

Screens

1000 900 800 700 600 0 0

1 2 3 4 5 Years Since 1995

6

61. Sample answer: 294

62. 2

63. 2

64.

65.

2 3

1 4

66. 2

67. 0.6

Lesson 11-5 

1. Sample answer:

Infinite Geometric Series Pages 602–604 n

1 a a 2b n1

2. 0.999999 . . . can be written as the infinite geometric 9 9 9   p. series 10

100

1000

The first term of this series is 9 and the common ratio is 10 9 1 10 , so the sum is 1 or 1. 10 1  10

©Glencoe/McGraw-Hill

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3. Beth; the common ratio for the infinite geometric series

4. 108

is  . Since `  `  1, the 4 3

4 3

series does not have a sum a and the formula S  1 1r does not apply. 5. does not exist 7.

6. does not exist

3 4

8.

9. 100 11.

73 99

30 7

10.

5 9

12.

175 999

13. 96 cm

14. 14

15. does not exist

16. 7.5

17. 45

18. 64

19. 16

20. does not exist

21.

54 5

22. 3

23. does not exist

24. 1

25. 1

26. 7.5

27.

2 3

28. 144

29.

3 2

30. 6

31. 2

32. 30 ft

33. 40  20 22  20  p

34. 80  40 22 or about 136.6 cm

35. 900 ft

36. 27, 18, 12

37. 75, 30, 12

38. 24, 16 , 11 , 7

1 5

1 2

7 25

64 125

39. 8, 3 , 1 , 

©Glencoe/McGraw-Hill

40.

298

11 32

409 512

7 9

Algebra 2

Chapter 11

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41.

1 9

42.

4 11

43.

82 99

44.

82 333

45.

427 999

46.

5 11

47.

229 990

48.

S  a1  a1r  a1r 2  a1r 3  p

()rS  a1r  a1r 2  a1r 3  a1r 4  p S  rS  a1  0  0 0 0  p S(1  r ) a1 a1 S 1r

49. The total distance that a ball bounces, both up and down, can be found by adding the sums of two infinite geometric series. Answers should include the following. • an  a1  r n1, Sn  a1(1  r n) , 1r

or S 

50. D

a1 1r

• The total distance the ball falls is given by the infinite geometric series 3  3(0.6)  3(0.6)2  p . The sum of this series is 3 or 7.5. The total 1  0.6

distance the ball bounces up is given by the infinite geometric series 3(0.6)  3(0.6)2  3(0.6)3  p . The sum of this series is 3(0.6) 1  0.6

or 4.5. Thus, the total distance the ball travels is 7.5  4.5 or 12 feet. 52. 182

51. C 53.

8744 81

54. 32.768% 56. 

55. 3 ©Glencoe/McGraw-Hill

299

3 2 Algebra 2

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57. x  5 59.

x  7 (x  3)(x  1)

61. (x  2)2  (y  4)2  36 1 2

63.  ,

58.

2a  5b 2 a b

60.

3x  7 (x  4)(x  2)

62. (x  3)2  (y  1)2  32

3 7 , 2 2

1 2

1 3

64.  ,  , 0,

1 2

65. x 2  36  0

66. x 2  9x  14  0

67. x 2  10x  24  0

68. about 180,724 visitors per year

69. The number of visitors was decreasing.

70. 2

71. 3

72. 2

1 2

74. 4

73.

75. 4

Lesson 11-6

Recursion and Special Sequences Pages 608–610

1. an  an1  d; an  r  an1

2. Sample answer: an  2an1  an2

3. Sometimes; if f(x)  x 2 and x1  2, then x2  22 or 4, so x2 x1. But, if x1  1, then x2  1, so x2  x1.

4. 12, 9, 6, 3, 0

5. 3, 2, 0, 3, 7

6. 0, 4, 4, 12, 20

7. 1, 2, 5, 14, 41

8. 5, 11, 29

9. 1, 3, 1

10. 3, 11, 123

11. bn  1.05bn1  10

12. $1172.41

13. 6, 3, 0, 3, 6

14. 13, 18, 23, 28, 33

15. 2, 1, 1, 4, 8

16. 6, 10, 15, 21, 28

17. 9, 14, 24, 44, 84

18. 4, 6, 12, 30, 84

19. 1, 5, 4, 9, 13

20. 4, 3, 5, 1, 9

©Glencoe/McGraw-Hill

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21.

7 7 7 7 7 , , , , 2 4 6 8 10

22.

3 3 15 25 425 , , , , 4 2 4 2 8

23. 67

24. 2.1

25. 1, 1, 2, 3, 5, . . .

26. the Fibonacci sequence

27. $99,921.21, $99,762.21, $99,601.29, $99,438.44,

28. 1, 3, 6, 10, 15

$99,841.95, $99,681.99, $99,520.11, $99,356.28

29. tn  tn1  n

30. 20,100

31. 16, 142, 1276

32. 5, 17, 65

33. 7, 16, 43

34. 4, 19, 94

35. 3, 13, 333

36. 1, 1, 1

37.

5 37 1445 , , 2 2 2

38.

4 10 76 , , 3 3 3

39. $75.77

40. No; according to the first two iterates, f(4)  4. According to the second and third iterates, f(4)  7. Since f(x) is a function, it cannot have two values when x  4.

41. Under certain conditions, the Fibonacci sequence can be used to model the number of shoots on a plant. Answers should include the following. • The 13th term of the sequence is 233, so there are 233 shoots on the plant during the 13th month. • The Fibonacci sequence is not arithmetic because the differences (0, 1, 1, 2, . . .) of the terms are not constant. The Fibonacci sequence is not geometric because the ratios 3 Q1, 2, , . . .R of the terms

42. D

2

are not constant. ©Glencoe/McGraw-Hill

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44. 27

43. C 1 6

46.

12 5

47. 5208

48.

1093 243

49. 3x  7 units

50. 120

51. 5040

52. 6

53. 20

54. 126

45.

55. 210

Lesson 11-7 The Binomial Theorem Pages 615–617 1. 1, 8, 28, 56, 70, 56, 28, 8, 1

2. n

3. Sample answer: (5x  y)4

4. 40,320

5. 17,160

6. 66

7. p5  5p4q  10p3q 2  10p 2q 3  5pq 4  q 5

8. t 6  12t 5  60t 4 

160t 3  240t 2  192t  64

9. x 4  12x 3y  54x 2y 2  108xy 3  81y 4

10. 56a5b3

11. 1,088,640a6b4

12. 10

13. 362,880

14. 6,227,020,800

15. 72

16. 210

17. 495

18. 2002

19. a 3  3a 2b  3ab 2  b 3

20. m4  4m 3n  6m 2n 2  4mn3  n4

21. r 8  8r 7s  28r 6s 2  56r 5s 3  70r 4s 4  56r 3s 5  28r 2s 6  8rs 7  s 8

22. m 5  5m 4a  10m 3a 2  10m 2a 3  5ma 4  a 5

23. x 5  15x 4  90x 3  270x 2  405x  243

24. a4  8a3  24a2  32a  16

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25. 16b4  32b3x  24b 2x 2  8bx 3  x 4

26. 64a6  192a5b  240a4b 2  160a3b3  60a2b4  12ab5  b6 28. 81x 4  216x 3y  216x 2y 2  96xy 3  16y 4

27. 243x 5  810x 4y  1080x 3y 2  720x 2y 3  240xy 4  32y 5 29.

a5 32



5a4 8

30. 243  135m  30m 2 

 5a3 

10m 3 3

20a2  40a  32



5m 4 27



31. 27x 3  54x 2  36x  8 cm3

32. 1, 4, 6, 4, 1

33. 45

34. 126x 4y 5

35. 924x 6y 6

36. 280x 4

37. 5670a4

38. 1,088,640a6b4

39. 145,152x 6y 3

40.

35 4 x 27

42.

12! 7!5!

63 8

41.  x 5

and

12! 6!6!

m5 243

represent the 6th

and 7th entries in the row for n  12 in Pascal’s triangle. 13! represents the seventh 7!6!

entry in the row for n  13. 13! 12! Since is below and 7!6! 7!5! 12! in Pascal’s triangle, 6!6! 12! 12! 13!   . 7!5! 6!6! 7!6!

43. The coefficients in a binomial expansion give the numbers of sequences of births resulting in given numbers of boys and girls. Answers should include the following. • (b  g)5  b5  5b4g  10b 3g 2  10b 2g 3  5bg 4  g 5;

©Glencoe/McGraw-Hill

44. D

303

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There is one sequence of births with all 5 boys, five sequences with 4 boys and 1 girl, ten sequences with 3 boys and 2 girls, ten sequences with 2 boys and 3 girls, five sequences with 1 boy and 4 girls, and one sequence with all 5 girls. • The number of sequences of births that have exactly k girls in a family of n children is the coefficient of bnkgk in the expansion of (b  g)n. According to the Binomial Theorem, this n! . coefficient is (n  k)!k!

45. C

46. 7, 5, 3, 1, 1

47. 3, 5, 9, 17, 33

48. 125 cm

49.

log 5 ; log 2

2.3219

50.

51.

log 8 ; log 5

1.2920

52. asymptotes: x  2, x  3

1 ; log 3

2.0959

53. asymptotes: x  4, x  1

54. hole: x  3

55. hyperbola

56. parabola

57. yes

58. no

59. True;

1(1  1) 2



1(2) 2

60. False;

or 1.

2(3) 2

61. True;

12(1  1)2 4

©Glencoe/McGraw-Hill



1(4) 4

(1  1)(2  1  1) 2



or 3.

62. True; 31  1  2, which is even.

or 1.

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Chapter 11 Practice Quiz 2 Page 617 1. 1,328,600

2. 364

3. 24

4.

5. 1, 5, 13, 29, 61

6. 2, 4, 8, 14, 22

7. 5, 13, 41

8. 243x 5  405x 4y  270x 3y 2  90x 2y 3  15xy 4  y 5

9. a6  12a5  60a4  160a3  240a 2  192a  64

Lesson 11–8

25 4

10. 4032a5b4

Proof and Mathematical Induction Pages 619–621

1. Sample answers: formulas for the sums of powers of the first n positive integers and statements that expressions involving exponents of n are divisible by certain numbers

2. Mathematical induction is used to show that a statement is true. A counter example is used to show that a statement is false.

3. Sample answer: 3n  1

4. Step 1: When n  1, the left side of the given equation is 1(1  1)

1. The right side is or 2 1, so the equation is true for n  1. Step 2: Assume 1  2  3 p k

k(k  1) 2

for

some positive integer k. Step 3: 1  2  3  p  k  1k  12   

©Glencoe/McGraw-Hill

305

k(k  1)  (k  1) 2 k(k  1)  2(k  1) 2 (k  1)  (k  2) 2

Algebra 2

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The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 1  2  3  p  n

n(n  1) 2

for all

positive integers n. 5. Step 1: When n  1, the left side of the given equation is 1 . 2 1 , 2

The right side is 1 

1 2

6. Step 1: 41  1  3, which is divisible by 3. The statement is true for n  1. Step 2: Assume that 4k  1 is divisible by 3 for some positive integer k. This means that 4k  1  3r for some whole number r. Step 3: 4k  1  3r 4k  3r  1 4k1  12r  4 4k1  1  12r  3 4k1  1  314r  12 Since r is a whole number, 4r  1 is a whole number. Thus, 4k1  1 is divisible by 3, so the statement is true for n  k  1. Therefore, 4n  1 is divisible by 3 for all positive integers n.

or

so the equation is true for

n  1. 1 1  2 2 2 1 1 1  p  k  1 k for some 3 2 2 2

Step 2: Assume

positive integer k. Step 3:

1 1  2 2 2 1 1 1  p  k  k1 3 2 2 2 1 1  1  k  k1 2 2 2 1  1  k1  k1 2 2 1  1  k1 2

The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 

1

1 2n

1 1 1 1  2 3 p n 2 2 2 2

for all positive

integers n.

©Glencoe/McGraw-Hill

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8. Sample answer: n  2

7. Step 1: 51  3  8, which is divisible by 4. The statement is true for n  1. Step 2: Assume that 5k  3 is divisible by 4 for some positive integer k. This means that 5k  3  4r for some positive integer r. Step 3: 5k  3  4r 5k  4r  3 5k1  20r  15 5k1  3  20r  12 5k1  3  415r  32 Since r is a positive integer, 5r  3 is a positive integer. Thus, 5k1  3 is divisible by 4, so the statement is true for n  k  1. Therefore, 5n  3 is divisible by 4 for all positive integers n. 9. Sample answer: n  3

10. Step 1: After the first guest has arrived, no handshakes have taken place.

1(1  1) 2

 0,

so the formula is correct for n  1. Step 2: Assume that after k guests have arrived, a total of

k(k  1) 2

handshakes have

take place, for some positive integer k. Step 3: When the (k  1)st guest arrives, he or she shakes hands with the k guests already there, so the total number of handshakes that have then taken place is k(k  1) 2

©Glencoe/McGraw-Hill

307

 k.

Algebra 2

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k(k  1) k(k  1)  2k k 2 2 k [(k  1)  2]  2 (k  1)k k (k  1) or  2 2

The last expression is the formula to be proved, where n  k  1. Thus, the formula is true for n  k  1. Therefore, the total number of handshakes is

for

all positive integers n. 12. Step 1: When n  1, the left side of the given equation is

11. Step 1: When n  1, the left side of the given equation is 1. The right side is 1[2(1)  1] or 1, so the equation is true for n  1. Step 2: Assume 1  5  9  p  (4k  3)  k (2k  1) for some positive integer k. Step 3: 1  5  9  p  (4k  3)  [4(k  1)  3]  k (2k  1)  [4(k  1)  3]  2k 2  k  4k  4  3  2k 2  3k  1  (k  1)(2k  1)  (k  1)[2(k  1)  1] The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 1  5  9  p  (4n  3)  n(2n  1) for all positive integers n.

©Glencoe/McGraw-Hill

n(n  1) 2

1[3(1)  1]

2. The right side is 2 or 2, so the equation is true for n  1. Step 2: Assume 2  5  8  p  (3k  1) 

k(3k  1) 2

for some positive integer k. Step 3: 2  5  8  p  (3k  1)  [3(k  1)  1] k(3k  1)  [3(k  1)  1] 2 k(3k  1)  2[3(k  1)  1]  2 2 3k  k  6k  6  2  2



3k 2  7k  4 2 (k  1)(3k  4)  2 (k  1)[3(k  1)  1]  2



308

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The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 2  5  8  p  n(3n  1)

(3n  1)  for all 2 positive integers n. 14. Step 1: When n  1, the left side of the given equation is 12 or 1. The right side is

13. Step 1: When n  1, the left side of the given equation is 13 or 1. The right side is 12(1  1)2 4

1[2(1)  1][2(1)  1] 3

or 1, so the equation is true for n  1. Step 2: Assume 13  23  33  p  k 3 

k 2 1k  12 2 4

the equation is true for n  1. Step 2: Assume 12  32  52  p (2k  1)2 

for

some positive integer k. Step 3: 13  2 3  33  p  k 3  (k  1)3      

k (2k  1)(2k  1) 3

for some

positive integer k. Step 3: 12  32  52  p  (2k  1)2  [2(k  1)  1]2

k 2(k  1)2  (k  1)3 4 k 2(k  1)2  4(k  1)3 4 2 2 (k  1) [k  4(k  1)] 4 2 2 (k  1) (k  4k  4) 4 2 (k  1) (k  2)2 4 2 (k  1) [(k  1)  1]2 4



k(2k  1)(2k  1)  3

[2(k  1)  1]2   

The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1.

©Glencoe/McGraw-Hill

or 1, so

  

309

k(2k  1)(2k  1)  3(2k  1)2 3 (2k  1)[k (2k  1)  3(2k  1)] 3 2 (2k  1)(2k  k  6k  3) 3 2 (2k  1)(2k  5k  3) 3 (2k  1)(k  1)(2k  3) 3 (k 1)[2(k 1)  1][2(k  1) 1] 3

Algebra 2

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Therefore, 13  23  33  p  n (n  1) 4 2

n3 

The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 12  32  52  p 

2

for all

positive integers n.

(2n  1)2 

n(2n  1)(2n  1) 3

for all positive integers n. 16. Step 1: When n  1, the left side of the given equation is

15. Step 1: When n  1, the left side of the given equation is 1 1 . The right side is a1 2 3 1 or , so the equation is 3

1 . 4

true

or , so the equation is true

1 3

p 



1 a1 2

3 3 1  kb for 3

1 3



1 32



1 33

3

1 43

some





1 1 1 a2  kb  k  1 2 3 3 1 1 1  k  k 1 2 23 3 3k  1  3  2 2  3k  1 3k  1  1 2  3k  1 1 3k  1  1 a b 2 3k  1

   

 p 

3k  1

1 2

©Glencoe/McGraw-Hill

p 

Step 3:

1

 a1 

4 4 1 1 1  a1  kb k 4 3 4

for some positive integer k. 1 4k

1 3k

1 4

for n  1. 1 1 Step 2: Assume  2 

positive integer k. Step 3:

1 3

1 4

for n  1. 1 1 1 Step 2: Assume  2  2  1 3k

The right side is a1  b

 b



1 4



1 42



1 43

 p 

1 k 1

4

1 1 1 kb  k  1 3 4 4 1 1 1  k  k 1 3 34 4 4k  1  4  3 3  4k  1 4k  1  1 3  4k  1 1 4k  1  1 a b 3 4k  1

 a1     

 a1  1 3

b 3k  1 1

310

k  1b

1

4

Algebra 2

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The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. 1 1 1 1 Therefore,  2  3  p  n

The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 

1 a1 2



1 1 1 1  2 3p n 3 3 3 3 1 b for all positive 3n

4

 a1  1 3

1 b 4n

4

4

4

for all positive

integers n.

integers n. 17. Step 1: 81  1  7, which is divisible by 7. The statement is true for n  1. Step 2: Assume that 8k  1 is divisible by 7 for some positive integer k. This means that 8k  1  7r for some whole number r. Step 3: 8k  1  7r 8k  7r  1 8k 1  56r  8 8k1  1  56r  7 8k 1  1  7(8r  1) Since r is a whole number, 8r  1 is a whole number. Thus, 8k1  1 is divisible by 7, so the statement is true for n  k  1. Therefore, 8n  1 is divisible by 7 for all positive integers n.

18. Step 1: 91  1  8, which is divisible by 8. The statement is true for n  1. Step 2: Assume that 9k  1 is divisible by 8 for some positive integer k. This means that 9k  1  8r for some whole number r. Step 3: 9k  1  8r 9k  8r  1 9k1  72r  9 9k1  1  72r  8 9k1  1  8(9r  1) Since r is a whole number, 9r  1 is a whole number. Thus, 9k 1  1 is divisible by 8, so the statement is true for n  k  1. Therefore, 9n  1 is divisible by 8 for all positive integers n.

19. Step 1: 121  10  22, which is divisible by 11. The statement is true for n  1. Step 2: Assume that 12k  10 is divisible by 11 for some positive integer k. This means that 12k  10  11r for some positive integer r.

20. Step 1: 131  11  24, which is divisible by 12. The statement is true for n  1. Step 2: Assume that 13k 11 is divisible by 12 for some positive integer k. This means that 13k  11  12r for some positive integer r.

©Glencoe/McGraw-Hill

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Step 3: 12k  10  11r 12k  11r  10 12k1  132r  120 12k1  10  132r  110 12k1  10  11(12r  10) Since r is a positive integer, 12r  10 is a positive integer. Thus, 12k 1  10 is divisible by 11, so the statement is true for n  k  1. Therefore, 12n  10 is divisible by 11 for all positive integers n.

Step 3: 13k  11  12r 13k  12r  11 13k 1  156r  143 13k 1  11  156r  132 13k 1  11  12(13r  11) Since r is a positive integer, 13r  11 is a positive integer. Thus, 13k1  11 is divisible by 12, so the statement is true for n  k  1. Therefore, 13n  11 is divisible by 12 for all positive integers n.

21. Step 1: There are 6 bricks in the top row, and 12  5(1)  6, so the formula is true for n  1. Step 2: Assume that there are k 2  5k bricks in the top k rows for some positive integer k. Step 3: Since each row has 2 more bricks than the one above, the numbers of bricks in the rows form an arithmetic sequence. The number of bricks in the (k  1)st row is 6  [(k  1)  1](2) or 2k  6. Then the number of bricks in the top k  1 rows is k 2  5k  (2k  6) or k 2  7k  6. k 2  7k  6  (k  1)2  5(k  1), which is the formula to be proved, where n  k  1. Thus, the formula is true for n  k  1.

22. Step 1: When n  1, the left side of the given equation is 1 a1. The right side is a1(1  r )

©Glencoe/McGraw-Hill

1r

or a1, so the equation is true for n  1. Step 2: Assume a1  a1r  a1r 2  p  a1r k1  a1(1  r k ) 1r

for some positive

integer k. Step 3: a1  a1r  a1r 2  p  a1r k1  a1r k    

a1(1  r k)  a1r k 1r a1(1  r k )  (1  r )a1r k 1r k a1  a1r  a1r k  a1r k  1 1r k  a1(1  r 1) 1r

The last expression is the right side of the equation to be proved, where n  k  1.

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Thus, the equation is true for n  k  1. Therefore, a1  a1r  a1r 2  p  a1r n1 

Therefore, the number of bricks in the top n rows is n 2  5n for all positive integers n.

a1(1  r n ) 1r

for all positive integers n. 23. Step 1: When n  1, the left side of the given equation is

24. Step 1: The figure shows how to cover a 21 by 21 board, so the statement is true for n  1.

1 2

a1. The right side is [2a1  (1  1)d ] or a1, so the equation is true for n  1. Step 2: Assume a1 (a1  d )  (a1  2d 2  p  [a1  (k  1)d ] 

k [2a1 2

 (k  1)d ] for

Step 2: Assume that a 2k by 2k board can be covered for some positive integer k.

some positive integer k. Step 3: a1  (a1  d )  (a1  2d )  p  [a1  (k  1)d ]  [a1  (k  1  1)d ] 

k [2a1 2

 (k  1)d ] 

k [2a1 2

 (k  1)d ]

[a1  (k  1  1)d ] 

 a1  kd

k [2a1  (k  1)d ]  2(a1  kd ) 2 2 k  2a1  (k  k)d  2a1  2kd  2 (k  1)2a1  (k 2  k  2k)d  2 (k  1)2a1  k(k  1)d  2 k1  (2a1  kd ) 2 k1 [2a1  (k  1  1)d ]  2



©Glencoe/McGraw-Hill

Step 3: Divide a 2k1 by 2k1 board into four quadrants. By the inductive hypothesis, the first quadrant can be covered. Rotate the design that covers Quadrant I 90 clockwise and use it to cover Quadrant II. Use the design that covers Quadrant I to cover Quadrant III.

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The last expression is the right side of the formula to be proved, where n  k  1. Thus, the formula is true for n  k  1. Therefore, a1  (a1  d )  (a1  2d )  p  [a1  (n  1)d ] 

Rotate the design that covers Quadrant I 90

counterclockwise and use it to cover Quadrant IV. This leaves three empty squares near the center of the board, as shown. Use one more L-shaped tile to cover these 3 squares. Thus, a 2k1 by 2k1 board can be covered. The statement is true for n  k  1. Therefore, a 2n by 2n checkerboard with the top right square missing can be covered for all positive integers n.

n [2a1 (n  1)d ] 2

for all positive integers n.

25. Sample answer: n  3

26. Sample answer: n  4

27. Sample answer: n  2

28. Sample answer: n  3

29. Sample answer: n  11

30. Sample answer: n  41

31. Write 7n as (6  1)n. Then use the Binomial Theorem. 7n  1  (6  1)n  1

32. An analogy can be made between mathematical induction and a ladder with the positive integers on the steps. Answers should include the following. • Showing that the statement is true for n  1 (Step 1). • Assuming that the statement is true for some positive integer k and showing that it is true for k  1 (Steps 2 and 3).

 6n  n  6n1 

n(n  1)  2

6n2  p  n  6  1  1  6n  n  6n1 

n(n  1)  2

6n2  p  n  6 Since each term in the last expression is divisible by 6, the whole expression is divisible by 6. Thus, 7n  1 is divisible by 6. 33. C

34. A

35. x 6  6x 5y  15x 4y 2  20x 3y 3  15x 2y 4  6xy 5  y 6

36. a7  7a6b  21a5b 2  35a4b3  35a3b4  21a 2b 5  7ab6  b7

©Glencoe/McGraw-Hill

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37. 256x 8  1024x 7y  1792x 6y 2  1792x 5y 3  1120x 4y 4  448x 3y 5  112x 2y 6  16xy 7  y 8

38. 4, 10, 28

39. 2, 14, 782

40. 12 h

41. 0, 1

42. 14

©Glencoe/McGraw-Hill

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Chapter 12 Probability and Statistics Lesson 12-1 The Counting Principle Pages 634–637 1. HHH, HHT, HTH, HTT, THH, THT, TTH, TTT

2. Sample answer: buying a shirt that comes in 3 sizes and 6 colors

3. The available colors for the car could be different from those for the truck.

4. independent

5. dependent

6. 30

7. 256

8. 20 10. dependent

9. D 11. independent

12. independent

13. dependent

14. 6

15. 16

16. 6

17. 30

18. 48

19. 1024

20. 240

21. 10,080

22. 151,200

23. 362,880

24. 17

25. 27,216

26. 160

27. 800

28. See students’ work.

©Glencoe/McGraw-Hill

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29. The maximum number of license plates is a product with factors of 26s and 10s, depending on how many letters are used and how many digits are used. Answers should include the following.

30. A

• There are 26 choices for the first letter, 26 for the second, and 26 for the third. There are 10 choices for the first number, 10 for the second, and 10 for the third. By the Fundamental Counting Principle, there are 263  103 or 17,576,000 possible license plates. • Replace positions containing numbers with letters. 31. C

32. 45

33. 20 mi

34. Step 1: When n  1, the left side of the given equation is 4. The right side is

1[3(1)  5] 2

or 4, so the equation is true for n  1. Step 2: Assume 4  7  10  p  (3k  1) 

k(3k  5) 2

for some positive integer k. Step 3: 4  7  10  p  (3k  1)  [3(k  1)  1]    

©Glencoe/McGraw-Hill

317

k(3k  5)  [3(k  1)  1] 2 k(3k  5)  2[3(k  1)  1] 2 2 3k  5k  6k  6  2 2 2 3k  11k  8 2

Algebra 2

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(k  1)(3k  8) 2 (k  1)[3(k  1)  5] 2

The last expression is the right side of the equation to be proved, where n  k  1. Thus, the equation is true for n  k  1. Therefore, 4  7  10  p n(3n  5)

 (3n  1)  2 for all positive integers n. 35. 28x 6 y 2

36. 280a3b4

37. 7

38. 5

39.

1 2

40. 1

41. 

x x  5y

42. 36 mi

43. 1, 2

44. 0, 2

45. y  (x  3)2  2

46. y  2(x  1)2  4

1 2

47. y   x 2  8

48. 4

49. 3

50. 4

1 R 3 53. no inverse exists 51.

2 3

55. y  x 

1 1 B 6 2

5 R 4 54. y  2x  2

1 1 B 7 4

52.

1 3

56. 60

57. 30

58. 840

59. 720

60. 6

61. 15

62. 56

63. 1

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Permutations and Combinations Pages 641–643 2. C (n, n  r)

1. Sample answer: There are six people in a contest. How many ways can the first, second, and third prizes be awarded?

  

n! [n  (n  r )]!(n  r )! n! r !(n  r )! n! (n  r )!r !

 C(n, r ) 3. Sometimes; the statement is only true when r  1.

4. 60

5. 120

6. 6

7. 6

8. combination; 15 10. permutation; 90,720

9. permutation; 5040 11. 84

12. 56

13. 9 15. 665,280

14. 2520 16. 10

17. 70

18. 792

19. 210

20. 27,720

21. 1260

22. permutation; 5040

23. combination; 28

24. permutation; 2520

25. permutation; 120

26. combination; 220

27. permutation; 3360

28. combination; 45

29. combination; 455

30. 11,880

31. 60

32. 75,287,520

33. 111,540

34. 267,696

35. 80,089,128

36. 528

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37. C (n  1,r ) C (n  1, r  1) 



(n  1)!  (n  1  r )!r ! (n  1)! [n  1  (r  1)] !(r  1)! (n  1)!  (n  r  1 )!r ! (n



   

38. Permutations and combinations can be used to find the number of different lineups. Answers should include the following. • There are 9! different 9-person lineups available: 9 choices for the first player, 8 choices for the second player, 7 for the third player, and so on. So, there are 362,880 different lineups. • There are C(16, 9) ways to choose 9 players from

(n (n (n (n

(n  1)!  r )! (r  1)! (n  1)! nr    r  1)!r ! n  r (n  1)! r   r )!(r  1)! r  1)!(n  r ) (n  1)!r  (n  r )!r ! (n  r )!r !  1)!(n  r  r ) (n  r )!r !

16: C (16, 9)  11,440.

16! 7!9!

or

(n  1)!n (n  r )!r ! n! (n  r )!r !

 C(n, r ) 39.

D

40. A

41. 24

42. 6

43. 120

44. 8

45. 80

46. Sample answer: n  3

47. Sample answer: n  2

48. 1.0986

49. x  0.8047

50. 21.0855

51. 20 days 53.

(y  4)2 9



52. (x  4) 2 4

1

x2 16



y2 9

1

7 53 2 2

54.  ;

55. 4; 128

56. {4, 4}

57. {2, 5}

58. e 3, f

59. 822

60. 0 x 3 0 y 3 23

61. 425

62. (1, 3)

©Glencoe/McGraw-Hill

1 3

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4 3

64. 

63. (0, 2) 65. 

6 7

66. 0

67. {7, 15}

68. 

69.

3 5

70.

1 2

71.

1 5

72.

1 3

Lesson 12-3 Probability Pages 647–650 1. Sample answer: The event July comes before June has a probability of 0. The event June comes before July has a probability of 1.

2.

3 5

3. There are 6  6 or 36 possible outcomes for the two dice. Only 1 outcome, 1 and 1, results in a sum of 2,

4.

1 7

6.

4 7

1

so P(2)  . There are 2 36 outcomes, 1 and 2 as well as 2 and 1, that result in a sum 2 1 of 3, so P(3)  or . 36

5.

18

2 7

7. 8:1

8. 1:5

9. 2:7

10.

6 11

11.

10 11

12.

2 7

13.

1 8

14.

3 8

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15.

1 10

16.

21 50

17.

2 25

18.

1 50

19.

6 55

20.

21 55

21.

28 55

22.

14 575

23.

11 115

24.

7 115

25.

6 115

26.

132 575

27.

24 115

28.

6 115

29. 0

30.

1 22,957,480

31. 0.007

32. 0.623

33. 0.109

34. 1:1

35. 3:5

36. 11:1

37. 5:3

38. 4:3

39. 1:4

40. 4:7

41. 3:1

42.

6 7

43.

3 10

44.

5 11

45.

4 9

46.

9 17

47.

1 9

48.

7 16

49.

3 5

50.

1 10

51. 2:23

52. 1:999

53. 1:4

54.

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540 1771

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55.

1 20

56.

9 20

57.

9 20

58.

1 20

59.

9 20

60.

9 20

61.

1 120

62.

1 

64. C

63. Probability and odds are good tools for assessing risk. Answers should include the following. • P(struck by lightning)  1 s , so  sf

750,000

odds  1:(750,000  1) or 1:749,999. P(surviving a lightning strike)  s sf

3 4

 , so odds 

3:(4  3) or 3 :1. • In this case, success is being struck by lightning or surviving the lightning strike. Failure is not being struck by lightning or not surviving the lightning strike. 1 36

65. D

66. theoretical;

67. experimental; about 0.307

68. experimental;

69. theoretical;

1 17

1 5

70. permutation; 120

71. permutation; 1260

72. combination; 35

73. 16

74. 24

75. direct variation

76. square root

77. (4, 4)

78. (1, 3)

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79.

6 35

80.

3 14

81.

1 4

82.

2 21

83.

9 20

Chapter 12 Practice Quiz 1 Page 650 1. 24

2. 756

3. 18,720

4. 1320

5. 56

6. permutation; 40,320

7. combination; 20,358,520

8.

1 221

10.

8 663

9.

13 102

Lesson 12-4 Multiplying Probabilities Pages 654–657 1. Sample answer: putting on your socks, and then your shoes

2. P(A, B, C, and D)  P(A)  P(B)  P(C)  P(D)

3. Mario; the probabilities of rolling a 4 and rolling a 2 are

4.

1 36

1 6

both . 5.

1 4

6.

1 17

7.

4 663

8.

7 30

9.

1 4

10.

1 16

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21 220

12. independent;

13.

1 12

14.

1 36

15.

25 36

16.

1 36

17.

1 6

18.

1 6

19.

5 6

20.

1 42

21.

1 49

22.

25 49

23.

10 21

24. 0

25. 0

26.

1 15 1 10

27.

2 15

28.

29.

2 15

30. dependent;

31. independent;

25 81

1 36

3 28

32. independent;

168 4913 1 32

33. dependent;

1 21

34. independent;

35. dependent;

81 2401

36.

1 9

First Spin

Second Spin R

R P(R,B) 

B 1 3



1 3

or

1 9

B

Y R B Y R B

Y

Y

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37.

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First Spin Blue Yellow Red 1 1 1 3 3 3 Blue 1 3 Second Spin

BB 1 9

BY 1 9

BR 1 9

Yellow YB 1 1 3 9

YY 1 9

YR 1 9

RY 1 9

RR 1 9

Red 1 3

RB 1 9

38.

1 3

39.

1 9

40.

1 635,013,559,600

41.

19 1,160,054

42.

1 158,753,389,900

43.

6327 20,825

44. a

99 4 b 100 1 1320

45. about 4.87%

46.

47. no

48. no

49. Sample answer: As the number of trials increases, the results become more reliable. However, you cannot be absolutely certain that there are no black marbles in the bag without looking at all of the marbles.

50. 21

51. Probability can be used to analyze the chances of a player making 0, 1, or 2 free throws when he or she goes to the foul line to shoot 2 free throws. Answers should include the following.

52. D

©Glencoe/McGraw-Hill

326

or about 0.96

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• One of the decimals in the table could be used as the value of p, the probability that a player makes a given free throw. The probability that a player misses both free throws is (1  p)(1  p) or (1  p) 2. The probability that a player makes both free throws is p  p or p 2. Since the sum of the probabilities of all the possible outcomes is 1, the probability that a player makes exactly 1 of the 2 free throws is 1  (1  p) 2  p 2 or 2p (1  p). • The result of the first free throw could affect the player’s confidence on the second free throw. For example, if the player makes the first free throw, the probability of making the second free throw might increase. Or, if the player misses the first free throw, the probability of making the second free throw might decrease. 53. C 55.

3 340

57. 1440 ways

1 204

56.

1 119

58. 6

59. 36

©Glencoe/McGraw-Hill

54.

60. x 2  4x  2

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61. x, x  4

62.

y

x

O

y  x2  x  2

63.

64.

y

O

y

x

O

x

y  x 2  3x

y  x2  4

65. 153

66. 9

69. (1, 2)

70. (13, 9)

71. (2, 4)

72.

2 3 5 4

67. 0 b 0

68. 5a 4 0 b 3 0

73.

5 6

74.

75.

11 12

76. 1

1 6

5 12

77. 1

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Lesson 12-5 Adding Probabilities Pages 660–663 1. Sample answer: mutually exclusive events: tossing a coin and rolling a die; inclusive events: drawing a 7 and a diamond from a standard deck of cards

2.

3. The events are not mutually exclusive, so the chance of rain is less than 100%.

4.

1 3

French and Algebra

French 150

5.

1 3

6.

1 3

7.

1 2

8.

5 6

9.

2 3

11. inclusive;

4 13

12.

13 16

14.

1 6

15.

25 42

16.

37 42

17.

35 143

18.

105 143

19.

3 143

20.

84 143

21.

38 143

22.

32 39

23. mutually exclusive;

©Glencoe/McGraw-Hill

Algebra 300

10. mutually exclusive;

13. 1

25. inclusive;

400

7 9

24. inclusive;

21 34

1 2

26. mutually exclusive;

329

2 13

4 13

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27.

4 13

28.

2 3

29.

55 221

30.

11 221

31.

188 663

32.

63 221

33.

1 8

34.

1 8

35.

1 4

36.

3 4

37.

1 780

38.

145 156

39.

9 130

40.

1 26

41.

11 780

42.

1 78

43.

3 5

44.

53 108

45.

17 27

46.

17 162

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47. Subtracting P(A and B) from each side and adding P (A or B) to each side results in the equation P (A or B)  P(A)  P(B)  P(A and B). This is the equation for the probability of inclusive events. If A and B are mutually exclusive, then P (A and B)  0, so the equation simplifies to P(A or B)  P(A)  P(B), which is the equation for the probability of mutually exclusive events. Therefore, the equation is correct in either case.

48. Probability can be used to estimate the percents of people who do the same things before going to bed. Answers should include the following. • The events are inclusive because some people brush their teeth and set their alarm. Also, you know that the events are inclusive because the sum of the percents is not 100%. • According to the information in the text and the table, P (read book)  38 and P (brush teeth)  100 81 . Since the events 100

are inclusive, P (read book and brush teeth)  P (read book)  P (brush teeth)  P (read book and brush 38 81   teeth)  100 1200 59  . 2000 100

49. C

100

50. A

51.

1 216

52.

125 216

53.

1 216

54.

1 8

55. 4:1

56. 1:8

57. 2:5

58. 5:3

59. 254

60. 24

61. (8, 10)

62. (12, 5)

63. (x  1)2(x  1)(x 2  1)

64. min: (0, 5); max: (1.33, 3.81)

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65. min: (0.42, 0.62); max: (1.58, 1.38)

66.

y

x

O

(0, 2), (2, 0), (0, 2); max: f(2, 0)  6; min: f (0, 2)  2 67.

68. d  12.79t

y

x

O

(1, 3), (1, 1), (3, 3), (3, 5); max: f(3, 5)  23; min: f (1, 1)  3 69. direct variation

70. 323.4, 298, no mode, 143

71. 35.4, 34, no mode, 72

72. 3.6, 3.45, 2.1, 3.6

73. 63.75, 65, 50 and 65, 30

74. 79.83, 89, 89, 57

75. 12.98, 12.9, no mode, 4.7

Lesson 12-6 Statistical Measures Pages 666–670 2. Sample answer: The variance of the set {0, 1} is 0.25 and the standard deviation is 0.5.

1. Sample answer: {10, 10, 10, 10, 10, 10} n

3. 

1 a (xi B n i1

 x )2

4. 40, 6.3

5. 8.2, 2.9

©Glencoe/McGraw-Hill

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7. $7300.50, $5335.25

8. The mean is more representative for the southwest central states because the data for the Pacific states contains the most extreme value, $10,650.

9. 2500, 50

10. 1.6, 1.3

11. 3.1, 1.7

12. 4.8, 2.2

13. 37,691.2, 194.1

14. 569.4, 23.9

15. 82.9, 9.1

16. 43.6, 6.6

17. 114.5, 105, 23

18. The mean and median both seem to represent the center of the data.

19. Mean; it is highest.

20. Mode; it is lower and is what most employees make. It reflects the most representative worker.

21. $1047.88, $1049.50, $695

22. Mode; it is the least expensive price.

23. Mean or median; they are nearly equal and are more representative of the prices than the mode.

24. 2,290,403; 2,150,000; 2,000,000

25. Mode; it is lowest.

26. Mean; it is highest.

27. 19.3

28. 28.9

29. 19.5

30. Washington; see students’ work.

31. 59.8, 7.7

32. 64%

33. 100%

34. Different scales are used on the vertical axes.

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35. Sample answer: The first graph might be used by a sales manager to show a salesperson that he or she does not deserve a big raise. It appears that sales are steady but not increasing fast enough to warrant a big raise.

36. Sample answer: The second graph might be shown by the company owner to a prospective buyer of the company. It looks like there is a dramatic rise in sales.

37. A: 2.5, 2.5, 0.7, 0.8; B: 2.5, 2.5, 1.1, 1.0

38. The first histogram is lower in the middle and higher on the ends, so it represents data that are more spread out. Since set B has the greater standard deviation, set B corresponds to the first histogram and set A corresponds to the second.

39. The statistic(s) that best represent a set of test scores depends on the distribution of the particular set of scores. Answers should include the following. • mean, 73.9; median, 76.5; mode, 94 • The mode is not representative at all because it is the highest score. The median is more representative than the mean because it is influenced less than the mean by the two very low scores of 34 and 19.

40. A

41. D

42. 3

43. 1.9

44. The mean deviations would be greater for the greater standard deviation and lower for the groups of data that have the smaller standard deviation.

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4 13

46. mutually exclusive;

47.

1 169

48.

4 663

49.

13 204

50.

1 16

51. 10, 92; 10, 21062; 

52. 3

53. 17

54. 2

9 5

55. 12 cm3

56. 14, 62

57. (1, 5)

58. (3, 5)

59. 136

60. 340

61. 380

62. 475

63. 396

64. 495

3 7

Chapter 12 Practice Quiz 2 Page 670 1.

3 20

2.

1 6

3.

2 9

4.

1 4

5.

1 6

6.

2 3

7.

3 4

8. 6.6, 2.6

9. 23.6, 4.9

©Glencoe/McGraw-Hill

10. 134.0, 11.6

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Lesson 12-7 The Normal Distribution Pages 673–675 1. Sample answer:

2. The mean of the three graphs is the same, but the standard deviations are different. The first graph has the least standard deviation, the standard deviation of the middle graph is slightly greater, and the standard deviation of the last graph is greatest.

the use of cassettes since CDs were introduced 3. Since 99% of the data is within 3 standard deviations of the mean, 1% of the data is more than 3 standard deviations from the mean. By symmetry, half of this, or 0.5%, is more than 3 standard deviations above the mean.

4. normally distributed

5. 68%

6. 13.5%

7. 95%

8. 6800

9. 250

10. 1600

11. 81.5%

12. positively skewed

13. normally distributed

14. Negatively skewed; the histogram is high at the right and has a tail to the left.

15. 68%

16. 34%

17. 0.5%

18. 16%

19. 50%

20. 50%

21. 95%

22. 50%

23. 815

24. 25

25. 16%

26. 652

27. The mean would increase by 25; the standard deviation would not change; and the

28. If a large enough group of athletes is studied, some of the characteristics may be

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graph would be translated 25 units to the right.

normally distributed; others may have skewed distributions. Answers should include the following. • 10

Frequency

8 6 4 2 0 67 68 69 70 71 72 73 74 75 76 77 78 79 80 Height (in.)

• Since the histogram has two peaks, the data may not be normally distributed. This may be due to players who play certain positions tending to be of similar large sizes while players who play the other positions tend to be of similar smaller sizes. 29. A

30. D

31. 17.5, 4.2

32. 42.5, 6.5

33.

2 13

34.

35.

4 13

36. 5, 0, 1 38. 1, 1

37. 3, 2, 4 39.

1 , 4

4 13

1

40.

y 50 2

1

1

O

2t

50 100

y  216t 2  53

about 45 min 41. 0.76 h

42. 21a 5b 2

43. 56c 5d 3

44. 126x 5y 4

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Lesson 12-8 Binomial Experiments Pages 678–680 1. Sample answer: In a 5-card hand, what is the probability that at least 2 cards are hearts?

2. RRRWW, RRWRW, RRWWR, RWRRW, RWRWR, RWWRR, WRRRW, WRRWR, WRWRR, WWRRR

3a. Each trial has more than two possible outcomes. 3b. The number of trials is not fixed. 3c. The trials are not independent.

4.

3 8

5.

1 8

6.

7 8

7.

1 28,561

8.

48 28,561

9.

27,648 28,561

10. about 0.05

11. about 0.37

12.

1 16

13.

1 16

14.

3 8

15.

1 4

16.

5 16

17.

11 16

18.

3125 7776

19.

125 3888

20.

625 648

21.

23 648

22.

243 1024

23.

1 1024

24.

15 1024

25.

135 512

26.

459 512

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27.

53 512

28.

105 512

29.

105 512

30.

319 512

31.

319 512

32. about 0.02

33. about 0.44

34.

560 2187

35. about 0.32

36.

1 3 15 5 15 3 1 , , , , , , 64 32 64 16 64 32 64

37.

1 4

38. C (n, m)p m(1  p)nm 40. 2

39. Getting a right answer and a wrong answer are the outcomes of a binomial experiment. The probability is far greater that guessing will result in a low grade than in a high grade. Answers should include the following. • Use (r  w)5  r 5  5r 4w  10r 3w 2  10r 2w 3  5rw 4  w 5 and the chart on page 676 to determine the probabilities of each combination of right and wrong. 1 5 4

• P(5 right): r 5  P a b 

1 1024

or about 0.098%; P (4 right, 1 wrong):

15 1024

or about

1.5%; P (3 right, 2 wrong): 1 3 3 2 4 4

10r 2w 3  10 a b a b 

45 512

or about 8.8%; P (3 wrong, 2 right): 10r 2w 3  1 2 3 3 4 4

10 a b a b 

135 512

or about

26.4%; P (4 wrong, 1 right):

©Glencoe/McGraw-Hill

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3 4 4

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5r w 4  5 a b a b  1 4

405 1024

or

about 39.6%; P (5 wrong): 5

w5  a b  3 4

243 1024

or about

23.7%. 41. B

42. See students’ work.

43. normal distribution

44. 68%

45. 10

46. 16%

47. Mean; it is highest.

48.

y x  3 x

O

49.

y

50.

xy4

y y  |5x |

x O

O

51. 0.1

52. 0.05

53. 0.039

54. 0.027

55. 0.041

56. 0.031

©Glencoe/McGraw-Hill

340

x

Algebra 2

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Lesson 12-9 Sampling and Error Pages 683–685 1. Sample answer: If a sample is not random, the results of a survey may not be valid.

2. Sample answer for good sample: doing a random telephone poll to rate the mayor’s performance; sample answer for bad sample: conducting a survey on how much the average person reads at a bookstore

3. The margin of sampling error decreases when the size of the sample n increases. As n p (1  p) increases, decreases.

4. Yes; last digits of social security numbers are random.

5. No; these students probably study more than average.

6. about 9%

7. about 4%

8. about 4%

n

9. The probability is 0.95 that the percent of Americans ages 12 and older who listen to the radio every day is between 72% and 82%.

10. about 283

11. No; you would tend to point toward the middle of the page.

12. Yes; all seniors would have the same chance of being selected.

13. Yes; a wide variety of people would be called since almost everyone has a phone.

14. No; freshmen are more likely than older students to be still growing, so a sample of freshmen would not give representative heights for the whole school.

15. about 8%

16. about 4%

17. about 4%

18. about 3%

19. about 3%

20. about 2%

21. about 4%

22. about 2%

23. about 3%

24. about 2%

©Glencoe/McGraw-Hill

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25. about 2%

26. about 3%

27. about 983

28. 36 or 64

29. A political candidate can use the statistics from an opinion poll to analyze his or her standing and to help plan the rest of the campaign. Answers should include the following. • The candidate could decide to skip areas where he or she is way ahead or way behind, and concentrate on areas where the polls indicate the race is close. • about 3.5% • The margin of error indicates that with a probability of 0.95 the percent of the Florida population that favored Bush was between 43.5% and 50.5%. The margin of error for Gore was also about 3.5%, so with probability 0.95 the percent that favored Gore was between 40.5% and 47.5%. Therefore, it was possible that the percent of the Florida population that favored Bush was less than the percent that favored Gore.

30. A

31. C

32.

1 32

5 32

34.

1 2

33.

35. 95%

36. 210

37. 97.5%

38. x  2, x  3

©Glencoe/McGraw-Hill

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Chapter 13 Trigonometry Lesson 13-1 Right Triangle Trigonometry Pages 706–708 2.

1. Trigonometry is the study of the relationships between the angles and sides of a right triangle.



hypotenuse

adjacent

opposite

8 15 ; cos   ; 17 17 8 17 tan   ; csc   ; 15 8 17 15 sec   ; cot   15 8

4. sin  

3. Given only the measures of the angles of a right triangle, you cannot find the measures of its sides.

5. sin  

285 ; 11

cos  

tan  

285 ; 6

csc  

sec  

11 ; 6

7. cos 23 

cot  

32 ; x

6 ; 11

5 6

6. sin   ; cos  

11 285 ; 85

6 285 85

x  34.8

tan  

5 211 ; 11

csc   ;

sec  

6 211 ; 11

cot  

8. tan x  

9. B  45, a  6, c  8.5

211 ; 6

15 ; 21

6 5

211 5

x  36

10. A  34, a  8.9, b  13.3

11. a  16.6, A  67, B  23

12. c  19.1, A  47, B  43

13. 1660 ft

14. B

15. sin  

4 ; 11

cos  

tan  

4 2105 ; csc 105

sec  

112105 ; 105

Glencoe/McGraw-Hill

2105 ; 11



3 5 3 tan   ; csc 4 5 sec   ; cot 4

11 ; 4

cot  

4 5 5  ; 3 4  3

16. sin   ; cos   ;

2105 4

343

 

Algebra 2

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17. sin  

27 ; 4

cos   ;

tan  

27 ; 3

csc  

3 4

4 3

sec   ; cot  

19. sin   tan  

18. sin  

4 27 ; 7

3 27 7

25 2 25 ; ; cos   5 5 1 ; csc   25; 2 25 ; 2

sec  

cot   2

21. tan 30 

x , 10

23. sin 54 

17.8 , x

25. cos x  

15 , 36

27a. sin 30 

opp hyp x 2x

sin 30 

cos 30

©Glencoe/McGraw-Hill

csc  

2106 ; 9

sec  

2106 ; 5

9 5

tan   ;

cot  

5 9

20. sin  

215 ; 8

cos   ;

tan  

215 ; 7

csc  

7 8

8 215 ; 15

7 215 15

3 x

22. cos 60  , x  6

x  22.0

24. tan 17.5 

x  65

26. sin x  

16 , 22

Replace opp with x and hyp with 2x.

x ; 23.7

sin 45  sin 45 

1 12

12 2 adj  hyp

sin 45  28b. cos 45

Simplify.

344

x  7.5

x  47

opp hyp x 12x

28a. sin 45 

sine ratio

1 Simplify. 2 adj cosine ratio  hyp 23x Replace adj with 13x and  2x hyp with 2x.

cos 30 

5 2106 ; 106

8 7

x  5.8

23 2

cos  

sec   ; cot  

sin 30  27b. cos 30

9 2106 ; 106

sine ratio Replace opp with x and hyp with 12x. Simplify. Rationalize the denominator. cosine ratio

cos 45 

x 12x

Replace adj with x and hyp with 12x.

cos 45 

1 12

Simplify.

cos 45 

12 2

Rationalize the denominator.

Algebra 2

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opp hyp

sine ratio

sin 60 

23x 2x

Replace opp with 13x and hyp with 2x.

sin 60 

23 2

Simplify.

27c. sin 60 

28c. tan 45  tan 45 

opp adj

tangent ratio

x x

Replace opp with x and adj with x.

tan 45  1

Simplify.

29. B  74, a  3.9, b  13.5

30. A  63, a  13.7, c  15.4

31. B  56, b  14.8, c  17.9

32. A  75, a  24.1, b  6.5

33. A  60, a  19.1, c  22

34. B  45, a  7, b  7

35. A  72, b  1.3, c  4.1

36. B  80, a  2.6, c  15.2

37. A  63, B  27, a  11.5

38. A  26, B  64, b  8.1

39. A  49, B  41, a  8, c  10.6

40. A  19, B  71, b  14.1, c  15

41. about 300 ft

42. about 142.8 ft

43. about 6

44. about 3.2 in.

45. 93.54 units2

46. about 1.72 km high

47. The sine and cosine ratios of acute angles of right triangles each have the longest measure of the triangle, the hypotenuse, as their denominator. A fraction whose denominator is greater than its numerator is less than 1. The tangent ratio of an acute angle of a right triangle does not involve the measure of the hypotenuse,

48. When construction involves right triangles, including building ramps, designing buildings, or surveying land before building, trigonometry is likely to be used. Answers should include the following. • If you view the ramp from the side then the vertical rise is opposite the angle that the ramp makes with the horizontal. Similarly, the horizontal run is the adjacent side. So the tangent of the angle is the ratio of the rise to the run or the slope of the ramp. • Given the ratio of the slope of ramp, you can find the angle of inclination by calculating tan–1 of this ratio.

opp . adj

If the measure of the opposite side is greater than the measure of the adjacent side, the tangent ratio is greater than 1. If the measure of the opposite side is less than the measure of the adjacent side, the tangent ratio is less than 1. ©Glencoe/McGraw-Hill

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49. C

50. 7.7

51. No; band members may be more likely to like the same kinds of music. 3 53. 8 15 55. 16 57. {2, 1, 0, 1, 2}

52. Yes; this sample is random since different kinds of people go to the post office. 1 54. 16

59. 20 qt

60. 35,904 ft

61. 12 m2

62. 48 L

Lesson 13-2

56. {222, 2i 22} 58. {121}

Angles and Angle Measure Pages 712–715

1. reals

2. In a circle of radius r units, one radian is the measure of an angle whose rays intercept an arc length of r units.

3.

4.

y

y

290˚

70˚ x

O

x

O

⫺70˚

5.

6.

y

y

300˚

570˚ O

©Glencoe/McGraw-Hill

x

O

346

x

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7.

y

O

⫺45˚

8.

13 18

10.

97 36

x

 18

9. 

11. 135

12. 30

13. 1140

14. 420, 300

15. 785, 295

16.

17. 21 h

18. 2 h

19.

7 , 3

5 3



20.

y 235˚

y 270˚

x

O

21.

22.

y

380˚

24.

y

x

O

y

O

⫺150˚

©Glencoe/McGraw-Hill

x

O

790˚

23.

y

x

O

x

O

347

⫺50˚

x

Algebra 2

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y

25.

26.

y

␲ O

x

x

O 2␲ ⫺ 3

27.

2 3

28.

 12

 3 5 4

29. 

30. 

31.

11 3

32.

19 6

33.

79 90

34.

13 9

35. 150

36. 495

37. 45

38. 60

39. 1305

40. 510

41.

1620 

 515.7

42.

540 

 171.9

43. Sample answer: 585, 135

44. Sample answer: 390, 330

45. Sample answer: 345, 375

46. Sample answer: 220, 500

47. Sample answer: 8, 352

48. Sample answer: 400, 320

49. Sample answer:

11 , 4

51. Sample answer:

3 , 4

53. Sample answer:

13 , 2

5 4

50. Sample answer:

19 , 6

13 4

52. Sample answer:

4 , 3

3 2

54. Sample answer:

25 , 4







5 6



8 3



7 4



55. 2689 per second; 47 radians per second

56. 209.4 in2

57. about 188.5 m2

58. number 17

59. about 640.88 in2

60a. a 2  (b)2  a 2  b 2  1 60b. b 2  a 2  a 2  b 2  1 60c. b 2  (a)2  a 2  b 2  1

©Glencoe/McGraw-Hill

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61. Student answers should include the following. • An angle with a measure of more than 180 gives an indication of motion in a circular path that ended at a point more than halfway around the circle from where it started. • Negative angles convey the same meaning as positive angles, but in an opposite direction. The standard convention is that negative angles represent rotations in a clockwise direction. • Rates over 360 per minute indicate that an object is rotating or revolving more than one revolution per minute.

62. C

63. D

64. a  3.4, c  6.0, B  56

65. A  22, a  5.9, c  15.9

66. A  35, a  9.2, b  13.1

67. c  0.8, A  30, B  60

68. about 8.98%

69. about 7.07%

70. permutation, 17,100,720

71. combination, 35

72. [g  h](x)  6x  8, [h  g](x)  6x  4

73. [g  h](x)  4x 2  6x  23, [h  g](x)  8x 2  34x  44

74. 1041.8

75. 1418.2 or about 1418; the number of sports radio stations in 2008

76.

2 23 3

77.

3 25 5

78.

2 26 3

79.

210 2

80.

214 2

81.

210 4

©Glencoe/McGraw-Hill

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Chapter 13 Practice Quiz 1 Page 715 1. A  42, a  13.3, c  17.9

2. A  59, B  31, b  10.8

3.

4. sin  

y

O

5.

⫺60˚

x

19 18

6.

10 2149 ; 149

cos  

7 2149 ; 149

tan  

10 ; 7

sec  

2149 ; 7

csc  

2149 ; 10

cot  

7 10

5 2

8. 396

7. 210 9. 305; 415

10.

5 ; 3

 3



Lesson 13-3 Trigonometric Functions of General Angles Pages 722–724 1. False; sec 0  tan 0 

0 r

r r

or 1 and

2. Sample answer: 190

or 0. 8 15 , cos    , 17 17 8 17 tan    , csc   , 15 8 17 15 sec    , cot    15 8

4. sin  

3. To find the value of a trigonometric function of , where  is greater than 90, find the value of the trigonometric function for , then use the quadrant in which the terminal side of  lies to determine the sign of the trigonometric function value of .

©Glencoe/McGraw-Hill

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5. sin   0, cos   1, tan   0, csc   undefined, sec   1, cot   undefined

6. sin  

7. 55

8.

22 , 2

cos  

22 , 2

tan   1, csc   22, sec   22, cot   1

y

 4

y 7␲ 4

235˚ O

O

x

'

'

9. 60

10. 

y

x

23 2

' O

x

⫺240˚

11. 1

12. 23

2 23 3

13. 

14. sin   csc  

23 , 2

2 23 , 3

cot    15. sin   

26 , 3

cos  

23 , 3

tan   22, cos   

tan   23, sec   2,

23 3

16. about 12.4 ft

26 , 2

sec   23 24 , 25 24 tan   , 7 25 sec   , 7

17. sin  

©Glencoe/McGraw-Hill

7 , 25 25 csc   , 24 7 cot   24

cos  

25 , cos 5 1  , csc  2

18. sin   tan 

sin  

351

25 , 5



2 25 , 5

 25,

cos   2,

Algebra 2

Chapter 13

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19. cos  

8 289 , 89

cos  

5 289 , 89 8 5

tan    , csc    sec  

289 , 5

3 4 5 5 3 5 tan    , csc    , 4 3 5 4 sec   , cot    4 3

20. sin    , cos   ,

289 , 8 5 8

cot   

22. sin   0, cos   1, tan   0, csc   undefined, sec   1, cot   undefined

21. sin   1, cos   0, tan   undefined, csc   1, sec   undefined, cot   0 23. sin   

22 , 2

cos  

22 , 2

tan   1, csc   22, sec   22, cot   1

25. 45

26 , 3

24. sin   

23 , 3

tan   22, csc   

26 , 2

sec   23, cot  

22 2

26. 60

y

cos   

y 240˚

315˚ O

27. 30

'

x

x

O '

y

28. 55

y

' O

x

'

⫺210˚

©Glencoe/McGraw-Hill

352

x

O ⫺125˚

Algebra 2

Chapter 13

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29.

 4

y

30.

 6

5␲ 6

5␲ 4

'

x

O

'

31.

y

 7

x

O

y

32.

 3

y

13␲ 7

O

33. 

'

x

23 2

36. 23

37. undefined

38.

1 2

39. 23

40.

22 2

41. undefined

42. 2

23 2

44. 1

45. 0.2, 0, 0.2, 0, 0.2, 0, and 0.2; or about 11.5, 0, 11.5, 0, 11.5, 0, and 11.5 4 5 5 csc    , 4 3 cot    4

46. 6092.5 ft

4 3 5 , 3

47. sin    , tan    ,

©Glencoe/McGraw-Hill

2␲ ⫺ 3

34. 2

35. 23

43.

x

O

'

sec  

48. sin  

226 , 26

5 226 , 26

cos   

csc   226, sec   

226 , 5

cot   5

353

Algebra 2

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2 22 , 3

49. cos   

tan   

22 , 4

2 25 , 5

50. sin   

csc   3, sec   

cos   

25 , 5

tan   2,

cot   222

csc   

25 , 2

sec   25

3 22 , 4

3 210 , 10

1 5

51. sin   

52. sin    , cos  

cos   

210 , 10

tan   3,

csc   

210 , 3

cot  

tan   

26 , 12

2 26 , 5

sec  

5 26 , 12

cot   226

1 3

53. about 173.2 ft

54. 45; 2 45 or 90 yields the greatest value for sin 2.

55. 9 meters

56. I, II

57. II

58. III

59. Answers should include the following. • The cosine of any angle is x defined as , where x is r the x-coordinate of any point on the terminal ray of the angle and r is the distance from the origin to that point. This means that for angles with terminal sides to the left of the y-axis, the cosine is negative, and those with terminal sides to the right of the y-axis, the cosine is positive. Therefore, the cosine function can be used to model real-world data that oscillate between being positive and negative.

60. C

©Glencoe/McGraw-Hill

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• If we knew the length of the cable we could find the vertical distance from the top of the tower to the rider. Then if we knew the height of the tower we could subtract from it the vertical distance calculated previously. This will leave the height of the rider from the ground. 61. a , 

62.

 2

63. 300

64.

900 

5 2

5 23 b 2

65. sin 28  67. sin x  

x , 12

5 , 13

 286.5

66. cos 43 

5.6

23

x , 83

60.7

68. 635

69. (7, 2)

70. (4, 3)

71. (5, 4)

72. 4.7

73. 15.1

74. 2.7

75. 32.9

76. 20.6

77. 39.6

Lesson 13-4 Law of Sines Pages 729–732 2. Sample answer: A  42, a  2.6 cm, b  3.2 cm

1. Sometimes; only when A is acute, a  b sin A, or a b and when A is obtuse, a b.

C 3.2 cm

A

2.6 cm

3.9 cm

B C

3.2 cm 2.6 cm

A 0.9 cm ©Glencoe/McGraw-Hill

355

B Algebra 2

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3. Gabe; the information given is of two sides and an angle, but the angle is not between the two sides, therefore the area formula involving sine cannot be used.

4. 57.5 in2

5. 6.4 cm2

6. C  30, a  2.9, c  1.5

7. B  80, a  32.0, b  32.6

8. B  20, A  20, a  20.2 10. two; B  42, C  108, c  5.7; B  138, C  12, c  1.2

9. no solution

11. one; B  24, C  101, c  12.0

12. one; B  19, C  16, c  8.7

13. 5.5 m

14. 43.1 m2

15. 19.5 yd2

16. 572.8 ft2

17. 62.4 cm2

18. 4.2 m2

19. 14.6 mi2

20. B  101, c  3.0, b  3.4

21. C  73, a  55.6, b  48.2

22. B  21, C  37, b  13.1

23. B  47, C  68, c  5.1

24. C  97, a  5.5, b  14.4

25. A  40, B  65, b  2.8

26. C  67, B  63, b  2.9

27. A  20, a  22.1, c  39.8

28. no

29. one; B  36, C  45, c  1.8

30. two; B  72, C  75, c  3.5; B  108, C  39, c  2.3

31. no

32. one; B  90, C  60, c  24.2

33. one; B  18, C  101, c  25.8

34. two; B  56, C  72, c  229.3; B  124, C  4, c  16.8

35. two; B  85, C  15, c  2.4; B  95, C  5, c  0.8

36. one; B  23, C  129, c  14.1

37. two; B  65, C  68, c  84.9; B  115, C  18, c  28.3

38. 4.6 and 8.5 mi

©Glencoe/McGraw-Hill

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39. 7.5 mi from Ranger B, 10.9 mi from Ranger A

40. 690 ft

41. 107 mph

42a. 14.63 b 20 42b. b  14.63 or b 20 42c. b 14.63

43. Answers should include the following. • If the height of the triangle is not given, but the measure of two sides and their included angle are given, then the formula for the area of a triangle using the sine function should be used. • You might use this formula to find the area of a triangular piece of land, since it might be easier to measure two sides and use surveying equipment to measure the included angle than to measure the perpendicular distance from one vertex to its opposite side. 1 • The area of ABC is ah.

44. D

2

C b

a h

A

sin B  Area  Area 

©Glencoe/McGraw-Hill

B

c h or h  c sin c 1 ah or 2 1 a (c sin B) 2

B

357

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45. B  78, a  50.1, c  56.1 47.

46.

23 3

48. 22

49. 660, 60 51.

17 , 6

53.

55 221

23 2

50. 407, 313

7 6



52.

3 68

54. 780 ft

55. 5.6

56. 7.8

57. 39.4

58. 136.0

Lesson 13-5 Law of Cosines Pages 735–738 1. Mateo; the angle given is not between the two sides, therefore the Law of Sines should be used.

©Glencoe/McGraw-Hill

2a. Use the Law of Cosines to find the measure of one angle. Then use the Law of Sines or the Law of Cosines to find the measure of a second angle. Finally, subtract the sum of these two angles from 180 to find the measure of the third angle. 2b. Use the Law of Cosines to find the measure of the third side. Then use the Law of Sines or the Law of Cosines to find the measure of a second angle. Finally, subtract the sum of these two angles from 180 to find the measure of the third angle.

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4. cosines; A  76, B  69, c  6.5

3. Sample answer:

15

9

13

5. sines; B  70, a  9.6, b  14

6. sines; C  101, B  37, c  92.5

7. cosines; A  23, B  67, C  90

8. 19.5 m 10. sines; A  60, b  14.3, c  11.2

9. 94.3 11. cosines; A  48, B  62, C  70

12. cosines; A  46, B  74, C  59.6

13. sines; B  102, C  44, b  21.0

14. cosines; A  56.8, B  82, c  11.5

15. sines; A  80, a  10.9, c  5.4

16. cosines; A  55, C  78, b  17.9

17. cosines; A  30, B  110, C  40

18. no

19. sines; C  77, b  31.7, c  31.6

20. cosines; A  103, B  49, C  28

21. no

22. cosines; A  15, B  131, C  34

23. cosines; A  52, C  109, b  21.0

24. sines; C  102, b  5.5, c  14.4

25. cosines; A  24, B  125, C  31

26. cosines; A  107, B  35, c  13.8

27. cosines; B  82, C  58, a  4.5

28. about 159.7

29. about 100.1

30. Since the step angle for the carnivore is closer to 180, it appears as though the carnivore made more forward progress with each step than the herbivore did.

©Glencoe/McGraw-Hill

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31. 4.4 cm, 9.0 cm

32. about 1362 ft; about 81,919 ft 2

33. 91.6

34. Since cos 90  0, a 2  b 2  c 2  2bc cos A becomes a 2  b 2  c 2.

35. Answers should include the following. • The Law of Cosines can be used when you know all three sides of a triangle or when you know two sides and the included angle. It can even be used with two sides and the nonincluded angle. This set of conditions leaves a quadratic equation to be solved. It may have one, two, or no solution just like the SSA case with the Law of Sines. • Given the latitude of a point on the surface of Earth, you can use the radius of the Earth and the orbiting height of a satellite in geosynchronous orbit to create a triangle. This triangle will have two known sides and the measure of the included angle. Find the third side using the Law of Cosines and then use the Law of Sines to determine the angles of the triangle. Subtract 90 degrees from the angle with its vertex on Earth’s surface to find the angle at which to aim the receiver dish.

36. B

37. A

38. 100.0

©Glencoe/McGraw-Hill

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39. Sample answer: 100.2

40. By finding the measure of angle C in one step using the Law of Cosines, only the given information was used. By finding this angle measure using the Law of Cosines and then the Law of Sines, a calculated value that was not exact was introduced; 100.0.

41. one; B  46, C  79, c  9.6

42. no solution

12 5 , cos   , 13 13 12 13 tan   , csc   5 12 13 5 sec   , cot   5 12

44. sin  

43. sin  

cos   csc   cot  

45. sin  

26 , 4

cos  

tan  

215 , 5

sec  

2 210 , 5

210 , 4

csc  

4 265 , 65 265 , 7 4 7

48. 4.3891

51. 540, 180

52.

5 , 2

54.

10 , 3

5 6



©Glencoe/McGraw-Hill

265 , 4

215 3

50. 390, 330

19 , 6

sec  

46. 1.3863

49. 405, 315

53.

7 4

tan   ,

2 26 , 3

cot  

47. {x 0 x 0.6931}

7 265 , 65

361

3 2



2 3



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Chapter 13 Practice Quiz 2 Page 738 1. sin  

3 213 , 13

2 23 3

2. 

2 213 , 13

cos   

3 2

tan    , csc   sec   

213 , 2

213 , 3 2 3

cot   

4. two; B  27; C  131; c  30.2; B  153; C  5; c  3.5

3. 27.7 m2

5. cosines; c  15.9, A  59, B  43

Lesson 13-6 Circular Functions Pages 742–745 1. The terminal side of the angle  in standard position must intersect the unit circle at P (x, y).

2. Sample answer: the motion of the minute hand on a clock; 60 s

3. Sample answer: The graphs have the same shape, but cross the x-axis at different points.

4. sin    , cos  

5. sin  

22 ; 2

cos  

12 13

22 2

6.

1 2

7. 

©Glencoe/McGraw-Hill

5 13

23 2

8. 720

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10.

9. 2 s

h 3

O

2

1

3

4

t

⫺3

4 5

5 13

3 5

13. sin  

15 ; 17

15. sin  

23 ; 2

cos  

8 17

1 2

14. sin    ; cos   1 2

cos   

1 2

18.

23 2

19. 1

20.

23 2

21. 1

22. 

22 2

9 4

23.

1 4

24.

25.

1  23 2

26. 23

27. 323

28. 1

29. 6

30. 9

31. 2

32. 8

1 440

13 2

16. sin   0.8; cos   0.6

17. 

33.

12 13

12. sin    ; cos   

11. sin   ; cos   

s

34. y 1

O ⫺1

©Glencoe/McGraw-Hill

363

1 440

1 220

Algebra 2

x

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1 13 1 13 b, a , b, 2 2 2 2

35. a ,

(1, 0), a ,  1 2

1 a , 2

37.



36. The population is around 425 near the 60th day of the year. It rises to around 625 in May/June. It falls to around 425 again by August/September. It continues to drop to around 225 in November/December.

13 b, 2

13 b 2

y x

38. tan  x y

39. 

40. cot 

41. 23

42. 

43. sine: D  {all reals}, R  {1 y 1}; cosine: D  {all reals}, R  {1 y 1}

44. Answers should include the following. • Over the course of one period both the sine and cosine function attain their maximum value once and their minimum value once. From the maximum to the minimum the functions decrease slowly at first, then decrease more quickly and return to a slow rate of change as they come into the minimum. Similarly, the functions rise slowly from their minimum. They begin to increase more rapidly as they pass the halfway point, and then begin to rise more slowly as they increase into the maximum. Annual temperature fluctuations behave in exactly the same manner.

©Glencoe/McGraw-Hill

364

23 3

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• The maximum value of the sine function is 1 so the maximum temperature would be 50  25(1) or 75 F. Similarly, the minimum value would be 50  25(1) or 25 F. The average temperature over this time period occurs when the sine function takes on a value of 0. In this case that would be 50 F. 23 3

45. A

46.

47. cosines; c  12.4, B  59, A  76

48. cosines; A  34, B  62, C  84

49. 27.0 in2

50. 12.5 m2

51. 6800

52. 9500

53. 5000

54. 5000

55. 250

56. 50

57. does not exist

58.

59. 8

60. 4x  5

61. 2x  9

62. 5y 2  4y  4 

63. 2y  7 

5 y3

64 3

11 y1

64. 20

65. 110

66. 73

67. 80

68. 56

69. 89

©Glencoe/McGraw-Hill

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Algebra 2

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Lesson 13-7

Inverse Trigonometric Functions Pages 749–751

1. Restricted domains are denoted with a capital letter.

2. Sample answer: Cos 45  Cos1

22 2

22 ; 2

 45

3. They are inverses of each other.

4.   Arctan x

5.   Arccos 0.5

6. 45

7. 0

8.   0.52

 6

9.   3.14

10. 0.22

11. 0.75

12. 0.66

13. 0.58

14. 30

15.   Arcsin 

16. a  Arctan b

17. y  Arccos x

18. 30  Arcsin

19. Arccos y  45

20. Arctan a b  x

21. 60

22. 30

23. 45

24. 30

25. 45

26. 90

27. 2.09

28. does not exist

29. 0.52

30. 0.52

31. 0.5

32. 0.66

33. 0.60

34. 0.5

35. 0.8

36. 0.81

37. 0.5

38. 3

39. 0.5

40. 1.57

41. 0.71

42. does not exist

43. 0.96

44. 0.87

©Glencoe/McGraw-Hill

1 2

4 3

366

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45. 60 south of west

46. 83

47. No; with this point on the terminal side of the throwing angle , the measure of  is found by solving the equation

48. 60

tan  

17 . Thus 18

  tan1

17 18

or about 43.4, which is greater than the 40 requirement. 49. 31

50. 102

51. Suppose P (x 1, y 1) and Q (x 2, y 2) lie on the line y  mx  b. Then m  y2  y1 . The tangent of

52. Trigonometry is used to determine proper banking angles. Answers should include the following. • Knowing the velocity of the cars to be traveling on a road and the radius of the curve to be built, then the banking angle can be determined. First find the ratio of the square of the velocity to the product of the acceleration due to gravity and the radius of the curve. Then determine the angle that had this ratio as its tangent. This will be the banking angle for the turn. • If the speed limit were increased and the banking angle remained the same, then in order to maintain a safe road the curvature would have to be decreased. That is, the radius of the curve would also have to increase, which would make the road less curved.

x2  x1

the angle  the line makes with the positive x-axis is opp equal to the ratio or adj

y2  y1 . x2  x 1

Thus tan   m.

y

Q (x 2, y 2) P (x , y 1)



x2 ⫺ x1

O

y2 ⫺ y1 x

y ⫽ mx m ⫹b

53. 37 ©Glencoe/McGraw-Hill

54. D 367

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56. Sin1 x  Cos1 x  for 2 all values of x.

55. 23 1 22 23 1 22  1 1   2 2 2 2 2 2          y 2 2 2 2 2 2 2 2 2 x 0

23 2

57. From a right triangle perspective, if an acute angle  has a given sine x, then the complementary angle    has that same value 2 as its cosine. This can be verified by looking at a right triangle. Therefore, the sum of the angle whose sine is x and the angle whose cosine  is x should be .

58.

59. 1

60. 1

61. sines; B  69, C  81, c  6.1 or B  111, C  39, C  3.9

62. cosines; A  13, B  77, C  90

63. 46, 39

64. 22, 57

65. 11, 109

66. 2.5 s

2

©Glencoe/McGraw-Hill

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Chapter 14 Trigonetmetric Graphs and Identities Lesson 14-1 Graphing Trigonometric Functions Pages 766–768 1. Sample answer: Amplitude is half the difference between the maximum and minimum values of a graph; y  tan  has no maximum or minimum value.

2. Sample answer: The graph repeats itself every 180.

3. Jamile; The amplitude is 3 and the period is 3.

4. amplitude: ; period 360 or 2

1 2

y 2.5 2 1.5 1 0.5 270˚ 180˚ 90˚ 1 1.5 2 2.5

90˚ 180˚ 270˚



6. amplitude: ; period 360 or 2

y

y

5 4 3 2 1

©Glencoe/McGraw-Hill

O

2 3

5. amplitude: 2; period: 360 or 2

270˚ 180˚ 90˚ 2 3 4 5

1

y  2 sin 

2 1.5 1 0.5

y  2 sin 

O

90˚ 180˚ 270˚



0.5 1 1.5 2

369

y

O

2 cos  3

90˚ 180˚ 270˚ 360˚

Algebra 2



Chapter 14

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8. amplitude: does not exist; period: 180 or 

7. amplitude: does not exist; period: 180 or 

y

y

2 1.5 1 0.5

2 1.5 1 0.5 270˚ 180˚ 90˚ 1 1 1.5 y  4 tan  2

O

90˚ 180˚ 270˚



O 270˚ 180˚ 90˚ 1 1.5 y  csc 2 2

9. amplitude: 4; period: 180 or 

10. amplitude: 4; period: 480 or

y 5 4 3 2 1

5 4 3 2 1 

90˚ 180˚ 270˚ 360˚

y 1.25 1 0.75 0.5 0.25

 30˚

60˚

O 90˚ 0.5 0.75 1 1.25

90˚ 120˚ 150˚ 1

y  2 sec 3

13. 12 months; Sample answer: The pattern in the population will repeat itself every 12 months.

©Glencoe/McGraw-Hill



3 4

2 3

2 1.5 1 0.5 60˚ 30˚ 1 1.5 2

90˚ 180˚ 270˚ 360˚ 450˚

12. amplitude: ; period: 720 or 4

y

O

3 4

y  4 cos 

O 1 2 3 4 5

11. amplitude: does not exist; period: 120 or

8 2

y

y  4 sin 2

O 1 2 3 4 5



90˚ 180˚ 270˚

3

1

y  4 cos 2 

90˚ 180˚ 270˚ 360˚ 450˚



14. 4250; June 1

370

Algebra 2

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15. amplitude: 3; period: 360 or 2

16. amplitude: 5; period: 360 or 2

y 5 4 3 2 1 270˚ 180˚ 90˚ 2 3 4 5

y 5 4 3 2 1

y  3 sin 

O

90˚ 180˚ 270˚

O 270˚ 180˚ 90˚ 2 3 4 5





y

y 10 8 6 4 2

5 4 3 2 1 O 270˚180˚90˚ 2 y  2 csc  3 4 5

90˚ 180˚ 270˚



270˚ 180˚ 90˚ 4 6 8 y  2 tan  10

1 5

y 1 0.8 0.6 0.4 0.2

90˚ 180˚ 270˚



y 10 8 6 4 2

1 y  5 sin 

O

O

20. amplitude: does not exist; period: 360 or 2

19. amplitude: ; period: 360 or 2

©Glencoe/McGraw-Hill

90˚ 180˚ 270˚

18. amplitude: does not exist; period: 180 or 

17. amplitude: does not exist; period: 360 or 2

270˚ 180˚ 90˚ 0.4 0.6 0.8 1

y  5 cos 

90˚ 180˚ 270˚



O 270˚180˚90˚ 4 6 1 y  3 sec  8 10

371

90˚ 180˚ 270˚

Algebra 2



Chapter 14

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21. amplitude: 1; period 90 or

 2

22. amplitude: 1; period: 180 or  y

y 5 4 3 2 1 270˚ 180˚ 90˚ 2 3 4 5

5 4 3 2 1

y  sin 4

O

90˚ 180˚ 270˚

period: 36 or

O 60˚ 30˚ 2 3 4 5

 5

y

30˚

60˚

O 72˚ 54˚ 36˚ 18˚ 2 3 4 y  cot 5 5



25. amplitude: does not exist; period: 540 or 3

18˚

36˚

54˚

72˚



26. amplitude: does not exist; period: 360 or 2 y

y

10 8 6 4 2

10 8 6 4 2

©Glencoe/McGraw-Hill



5 4 3 2 1

5 4 3 2 1

810˚ 540˚270˚ 4 6 1 y  4 tan 3  8 10

90˚ 180˚ 270˚

24. amplitude: does not exist;

2 3

y

y  sec 3

O

270˚ 180˚ 90˚ 2 3 4 5



23. amplitude: does not exist; period: 120 or

y  sin 2

O

270˚ 540˚ 810˚



O 540˚ 360˚ 180˚ 4 6 1 y  2 cot 2  8 10

372

180˚ 360˚ 540˚

Algebra 2



Chapter 14

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27. amplitude: 6; period: 540 or 3

28. amplitude: 3; period: 720 or 4

y 10 8 6 4 2 270˚ 180˚ 90˚ 4 6 8 10

y 2 y  6 sin 3 

O

90˚ 180˚ 270˚

10 8 6 4 2 

O 540˚360˚180˚ 4 6 8 10

29. amplitude: does not exist; period: 720 or 4

2

y

10 8 6 4 2 O 540˚360˚180˚ 4 1 y  3 csc 2  6 8 10

180˚ 360˚ 540˚

10 8 6 4 2



135˚ 90˚ 45˚ 4 6 1 y  2 cot 2 8 10

O

45˚



90˚ 135˚

8 9

31. amplitude: does not exist; period: 180 or 

32. amplitude: ; period: 600 or 10 3

y 10 8 6 4 2

©Glencoe/McGraw-Hill



180˚ 360˚ 540˚

30. amplitude: does not exist;  period: 90 or

y

O 270˚180˚ 90˚ 4 6 2y  tan  8 10

1

y  3 cos 2 

y

90˚ 180˚ 270˚

5 4 3 2 1



540˚360˚180˚ 2 3 4 5

373

3 2 3 y  3 sin 5  4

O

180˚ 360˚ 540˚

Algebra 2



Chapter 14

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33.

34. y

y 5 4 3 2 1 135˚ 90˚ 45˚ 2 3 4 5

y 35.

3 5

5 4 3 2 1

3

y  5 sin 4

O

45˚

90˚ 135˚



7

y  8 cos 5 

O

135˚ 90˚ 45˚ 2 3 4 5

y

sin 4

1 107

7 8

45˚

90˚ 135˚

cos 5

36. y  0.25 sin 128t, y  0.25 sin 512t, y  0.25 sin 1024t 38. f (x )  cos x and f (x )  sec x

37. Sample answer: The amplitudes are the same. As the frequency increases, the period decreases.

f (x ) 5 4 3 2 1

f (x )  cos x f (x )  cos (x )

O 270˚ 180˚ 90˚ 2 3 4 5

x

90˚ 180˚ 270˚

f (x ) f (x )  sec x f (x )  sec (x )

5 4 3 2 1

O 270˚180˚90˚ 2 3 4 5

©Glencoe/McGraw-Hill

374

90˚ 180˚ 270˚

Algebra 2

x

Chapter 14

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39. y  2 sin

 5

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t

40. y 

2.5 2 1.5 1 0.5 0.5 1 1.5 2 2.5

y  2 sin 5 t

O

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

41. about 1.9 ft

42. Sample answer: Tides display periodic behavior. This means that their pattern repeats at regular intervals. Answers should include the following information. • Tides rise and fall in a periodic manner, similar to the sine function. • In f (x )  a sin bx, the amplitude is the absolute value of a.

43. A

44. C

45. 90

46. 90

47. 45

48.

1 2

49.

22 2

50.

22 2

51.

13 16

52. 3, 11, 27, 59, 123

©Glencoe/McGraw-Hill

375

Algebra 2

t

Chapter 14

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53.

2:03 PM

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54.

y 15 13 11 9 7 5 3 1 8

4

y x

15 13 11 9 7 5 3 1

2

y  3x 2

O

4

8

x

8

3 5

55.

8

4

15 13 11 9 7 5 3 1 O

y  2x 2

4

8

x

8

O

4

3 5

x

8

y  3x 2  4

4

15 13 11 9 7 5 3 1 O

y  (x  3)2  2 4

x

8

3 5

Translations of Trigonometric Graphs Pages 774–776

1. vertical shift: 15; amplitude: 3; period: 180; phase shift: 45

©Glencoe/McGraw-Hill

y  3x 2

y

y  x2  2

3 5

Lesson 14-2

4

56.

y

y  2(x  1)2

y

2. The midline of a trigonometric function is the line about which the graph of the function oscillates after a vertical shift.

376

Algebra 2

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3. Sample answer: y  sin (  45)

4. 1; 2;

 2 y

(



y  sin   2



5. no amplitude; 180; 60

3 2

)

   2

5 4 3 2 1 O

 2

2 3 4 5



3 2



6. 1; 360; 45 y

y 5 4 3 2 1

0.75

y  cos (  45˚)

0.5

O 270˚180˚ 90˚ 2 3 y  tan (  60˚) 4 5

90˚ 180˚ 270˚

0.25



O 45˚ 0.25

45˚ 90˚ 135˚ 180˚ 225˚



0.5 0.75

 3

7. no amplitude; 2;  (



y  sec   3



3 2

)

1 ; 4

1 4

y  ; 1; 360 y

y 4 3 2 1

O    1 2 2 3 4

©Glencoe/McGraw-Hill

8.

 2



3 2

5 4 3 2 1



O 270˚ 180˚ 90˚ 2 3 4 5

377

1

y  cos   4

90˚ 180˚ 270˚

Algebra 2



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9. 5; y  5; no amplitude; 360

10. 4; y  4; no amplitude; 180 y 7

y

6

10 8 6 4 2

5 4

O 270˚180˚90˚ 4 6 8 y  sec   5 10

1 135˚ 90˚ 45˚

y  sin   0.25

0.5

90˚

180˚

270˚

45˚

y  3 sin [2(  30˚)]  10 14 12 10 8 6 4 2

1

0.5

O 1

90˚

135˚



12. 10; 3; 180; 30

y

O

2



90˚ 180˚ 270˚

11. 0.25; y  0.25; 1; 360 1.5

3

y  tan   4

360˚



y

O 270˚ 180˚ 90˚ 4

1



90˚ 180˚ 270˚

1.5

  2 4

13. 6; no amplitude; 60; 45

14. 1; no amplitude; ;

y

y

1 45˚

©Glencoe/McGraw-Hill

O 2 3 4 5 6 7 8 9 10 11

45˚

4 3 2 1





3 8



 4



 1O 8

2 3 4 1 y  2 sec 4   4  1

y  2 cot (3  135˚)  6

[(

378

 8

 4

3 8



)]

Algebra 2

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 6

2 3

15. 2; ; 4; 

16. 4; 1; 4 s

y 1 O 3 2  1



2

3



2 3

2

[ 1(



y  3 cos 2   6

)]  2



17. h  4  cos t or 2 h  4  cos 90t

18.

h



h  4  cos 2 t

6 5 4 3 2 1 O 1 2 3 4

19. 1; 360; 90

1

2

O 270˚ 180˚ 90˚ 2 3 4 5

©Glencoe/McGraw-Hill

4

t

20. no amplitude; 180; 30 y

y 5 4 3 2 1

3

5 4 3 2 1

y  cos (  90˚)

90˚ 180˚ 270˚



O 135˚ 90˚ 45˚ 2 3 4 5

379

45˚

90˚ 135˚



y  cot (  30˚)

Algebra 2

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21. 1; 2;

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 3

 4

22. 1; 2; 

y

y 5 4 3 2 1 

3 2



(

y  sin   4

5 4 3 2 1

) 

O    2 2 3 4 5

 2



3 2



23. no amplitude; 180; 22.5

3 2

O    2 2 3 4 5

5 4 3 2 1 45˚

90˚ 135˚





3 2



y  3 sin (  75˚)

O 270˚ 180˚ 90˚ 2 3 4 5

1 y  4 tan (  22.5˚)

90˚ 180˚ 270˚



26. 2; y  2; no amplitude; 360

25. 1; y  1; 1; 360 y

y

5 4 3 2 1

©Glencoe/McGraw-Hill

 2

)

y

5 4 3 2 1

O 270˚ 180˚ 90˚ 2 3 y  sin   1 4 5



24. 3; 360; 75

y

O 135˚ 90˚ 45˚ 2 3 4 5

(

y  cos   3

5 4 3 2 1



O 270˚180˚90˚ 2 3 y  sec   2 4 5

90˚ 180˚ 270˚

380

90˚ 180˚ 270˚

Algebra 2



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3 4

y

360

2 1

y

O 270˚ 180˚ 90˚ 2 3 4 5 6 7 8

29.

1 ; 2

3 4

28.  ; y   ; no amplitude;

27. 5; y  5; 1; 360

90˚ 180˚ 270˚

5 4 3 2 1



O 270˚180˚90˚ 2 3 3 y  csc   4 4 5

y  cos   5

1 1 2 2

30. 1.5; y  1.5; 6; 360

y  ; ; 360

y y 5 4 3 2 1

1

1

90˚ 180˚ 270˚

y  6 cos   1.5

10 8 6 4 2

y  2 sin   2

O 270˚ 180˚ 90˚ 2 3 4 5

O 270˚ 180˚ 90˚ 4 6 8 10



32.

31. 18 16 14 12 10 8 6 4 2 3  2 4



4

O

(



y  5  tan   4

 4

 2

3 4

O 270˚ 180˚ 90˚ 2 3 4 5

)

2 y  3 cos (  50˚)  2

90˚ 180˚ 270˚



translation 50 right and 2 units up with an amplitude 2 of unit





3

translation units left and 4 5 units up

©Glencoe/McGraw-Hill



90˚ 180˚ 270˚

y 5 4 3 2 1

y





90˚ 180˚ 270˚

381

Algebra 2

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34. 5; 4; 180; 30

33. 1; 2; 120; 45 y 5 4 3 2 1

y 10 8 6 4 2

y  2 sin [3(  45˚)]  1



O

270˚ 180˚ 90˚ 2 3 4 5

270˚ 180˚ 90˚ 4 6 8 10

90˚ 180˚ 270˚

35. 3.5; does not exist; 720; 60

90˚ 180˚ 270˚



y  4 cos [2(  30˚)]  5

36. 0.75; does not exist; 270; 90 y 20 16 12 8 4

y 8 6 4 2 O 270˚180˚90˚ 4 6 8 10 12

O

90˚ 180˚ 270˚

[1 (



270˚180˚90˚ 8 12 16 20

)]

y  3 csc 2   60˚  3.5

O

90˚ 180˚ 270˚

[2(



)]

y  6 cot 3   90˚  0.75

1 4

38. 4; does not exist; 30;22.5

37. 1; ; 180; 75

y y 5 4 3 2 1

O 270˚ 180˚ 90˚ 2 3 4 5

2 1

1 y  4 cos (2  150˚)  1

22.5˚ 90˚ 180˚ 270˚



O

22.5˚

2 3 4 5 6 7 8



2 y  5 tan (6  135˚)  4

©Glencoe/McGraw-Hill

382

Algebra 2

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 4

2 3

40. 4; does not exist; 6; 

39. 3; 2; ; 

y

y 8 7 6 5 4 3 2 1 

3 2

[(

O

  



y  3  2 sin 2   4

 2

2 2



3 2

16 14 12 10 8 6 4 2

)]



O 4 2 4

2

[1(

4 2

y  4  sec 3   3

41.

42.

1

5 4 3 2 1 

3 2

   2

y y  3  2 cos  1 y  3  cos (  )

 2

2 3 4 5



3 2

)]

y 5 4 3 2 1

2

O





O 4 2 2 3 4 5

The graphs are identical.

[ 1 (  )] 1 3 y  cos [ 4 (  2 )] y  sin 4   2

2

4



The graphs are identical. 43. c

44. 180; 5 yr

45. 300; 14.5 yr

46. Sample answer: When the prey (mouse) population is at its greatest the predator will consume more and the predator population will grow while the prey population falls.  9

47. h  9  6 sin c (t  1.5)d

48. a  1, b  1, h 

49. Sample answer: You can use changes in amplitude and period along with vertical and horizontal shifts to show an animal population’s starting point and display changes to that population over a period of

50. B

©Glencoe/McGraw-Hill

383

 2

Algebra 2

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time. Answers should include the following information. • The equation shows a rabbit population that begins at 1200, increases to a maximum of 1450, then decreases to a minimum of 950 over a period of 4 years. • Relative to y  a cos bx, y  a cos bx  k would have a vertical shift of k units, while y  a cos [b (x  h)] has a horizontal shift of h units. 52. amplitude: does not exist; period: 360 or 2

51. D

y 5 4 3 2 1 O 270˚180˚90˚ 2 3 y  3 csc  4 5

period: 270 or

y

3 2

y

5 4 3 2 1

10 8 6 4 2

 y  sin 2

O

90˚ 180˚ 270˚



360˚ 180˚ 4 6 2 y  3 tan  3 8 10

O

180˚ 360˚



56. 0.57

55. 0.75 ©Glencoe/McGraw-Hill



54. amplitude: does not exist;

53. amplitude: 1; period: 720 or 4

270˚ 180˚ 90˚ 2 3 4 5

90˚ 180˚ 270˚

384

Algebra 2

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57. 0.83

58. 0.8

59. 35

60. 2.29

61. 0.66

62. 0.66

63.

5a  13 (a  2)(a  3)

64. 

65.

3y 2  10y  5 2(y  5)(y  3)

66. 

1 4

67. 1

23 2

68. 1

69.

1 2

70. 0

71.

23 3

72. 

22 2

73. 1

Lesson 14-3 Trigonometric Identities Pages 779–781 1. Sample answer: The sine function is negative in the third and fourth quadrants. Therefore, the terminal side of the angle must lie in one of those two quadrants.

2. Sample answer: Pythagorean identities are derived by applying the Pythagorean Theorem to trigonometric concepts.

3. Sample answer: Simplifying a trigonometric expression means writing the expression as a numerical value or in terms of a single trigonometric function, if possible.

4. 

5 4

3 5

5. 

6.

7. 22

8. 1 10. sec 

9. tan2 

12. sin   cos 

11. csc 

©Glencoe/McGraw-Hill

23 3

385

v2 gR

Algebra 2

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13.

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1 2

14.

15. 25

25 3

16. 2 22 3 5

17.

5 4

18.

19.

23 2

20. 

21.

3 4

22.

3 25 5

4 5 4 217 17

4 27 7

23. 

24. 

25. cot 

26. 1

27. cos 

28. sin 

29. 2

30. 3

31. cot2 

32. tan 

33. 1

34. cot2 

35. csc2 

36. 1

37. about 11.5

38. about 4 m/s

39. about 9.4

40. E 

I tan  cos  E I sin  simplifies to E  . R2

42. P  I 2R sin2 2ft

41. No; R 2 

43. P  I 2R 

I 2R . 1  tan2 2ft

44.

45. Sample answer: You can use equations to find the height and the horizontal distance of a baseball after it has been hit. The equations involve using the initial angle the ball makes with the ground with the sine function. Answers should include the following information.

©Glencoe/McGraw-Hill

I cos  R2

9 16

46. B

386

Algebra 2

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• Both equations are quadratic in nature with a leading negative coefficient. Thus, both are inverted parabolas which model the path of a baseball. • model rockets, hitting a golf ball, kicking a rock 48. 1; y  1; 1; 360

47. A

y 5 4 3 2 1 O 270˚ 180˚ 90˚ 2 3 4 5

49. 12; y  12; no amplitude; 180 20

y  sin   1

y 5 4 3 2 1

15 10 5

©Glencoe/McGraw-Hill



50. amplitude: does not exist; period: 180 or 

y

O 270˚ 180˚ 90˚ 5 y  tan   12

90˚ 180˚ 270˚

90˚ 180˚ 270˚

O 135˚ 90˚ 45˚ 2 3 y  csc 2 4 5



387

45˚

90˚ 135˚

Algebra 2



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51. amplitude: 1; period: 120 or

2 3

52. amplitude: does not exist; period: 36 or

y 5 4 3 2 1

 5

y 5 4 3 2 1

y  cos 3

O 135˚ 90˚ 45˚ 2 3 4 5

45˚

90˚ 135˚



1

y  3 cot 5

O

22.5˚



22.5˚

2 3 4 5

1 6

53. 93

54. y   (x  11)2 

55. Symmetric ()

56. Substitution ()

57. Multiplication ()

58. Substitution ()

1 2

Chapter 14 Practice Quiz 1 Page 781 1.

3 , 4

2. 5, 2, 8,

720 or 4 y 5 4 3 2 1

270˚ 180˚ 90˚ 2 3 4 5

y

3

6 4 2

1

y  4 sin 2 

O

90˚ 180˚ 270˚

O 4 2 4 6 8 10 12 14



3 5

3.  5.

 4

4. 

2

4

[1 (





y  2 cos 4   4

)]  5

213 3

25 2

©Glencoe/McGraw-Hill

388

Algebra 2

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Lesson 14-4

Page 389 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-14:

Verifying Trigonometric Identities Pages 784–785

?

1. sin  tan   sec   cos  ?

sin  tan  

1 cos 

2. Sample answer: Use various identities, multiply or divide terms to form an equivalent expression, factor, and simplify rational expressions.

 cos 

sec  

1 cos 

1 cos2   , cos  cos  Multiply by the LCD, cos . ? 1  cos2  tan   cos  Subtract. 1  cos 2  ? sin2  tan    sin2  cos  sin  ? tan   sin   cos  Factor. ?

sin  tan   sin  sin  sin 

sin  tan   sin  tan 

sin   tan  cos  ?

3. Sample answer: sin2   1  cos2 ; it is not an identity because sin 2   1  cos2 . 5.

4. tan (cot   tan )  sec 2  ?

1  tan2   sec2  sec2   sec2 

?

tan2  cos2   1  cos2  sin2  cos2 

6.

?

 cos2   sin2  sin2   sin2 

cos2  1  sin  1  sin2  1  sin  (1  sin )(1  sin ) 1  sin 

?

 1  sin  ?

 1  sin  ?

 1  sin 

1  sin   1  sin 

©Glencoe/McGraw-Hill

389

Algebra 2

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7.

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1  tan2  csc2 

 tan2 

sec2  csc2 

 tan2 

Page 390 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-14:

?

8.

?

cos 

1 cos 2  ?  1 ?

tan2 

sin  cos 

sin  sec  sin  sec  sin  sec 

 sin   tan  2

2

tan2   tan2 

9.

sec   1 tan 

?



sec   1 tan  sec   1 tan  sec   1 tan  sec   1 tan 

11.

?

 ?

 ?

 

tan  sec   1

sin2  cos2 

?

12. cot  (cot   tan )  csc2 

?

cot2   cot  tan   csc2 

?

 cos2   1 2

cot 2  

?



cos  sin 

?

 csc 2  ?

?

14.

?

?

sin  sec  cot   1 sin  

 sin2   sec2 

1 cos 



cos  sin 

?

1

11

?

1  tan2   sec2  sec2   sec2 

©Glencoe/McGraw-Hill

sin  cos 

cot2   1  csc2  csc2   csc2 

1  sec2  sin2   sec2  1 cos2 



?

cos   sin   1 11

1

?



sin  cos  sin2   cos2  sin  cos  1 sin  sec 

tan  sec   1  sec   1 sec   1 tan   (sec   1) sec2   1 tan   (sec   1) tan2  sec   1 tan 

2

13.

?



10. D

cos2   tan2  cos2   1 cos2  

cos 

sin  ? 1  sin2   cos2  sec 

sin 2 

1 cos2 

1 sin  ?  sec  tan   cot  sin  ? 1  sin2  sin  sec  

390

Algebra 2

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1  2 cos2  ?  tan   cot  sin  cos  (1  cos2 )  cos2  ?  tan   cot  sin  cos  sin2   cos2  ?  tan   cot  sin  cos  sin2  cos2  ?   tan   cot  sin  cos  sin  cos  sin  cos  ?   tan   cot  cos  sin  tan   cot   tan   cot 

16.

15. 1  cos  ?  (csc   cot )2 1  cos  1  cos  ?  csc2   2 cot  csc  1  cos   cot2  1  cos  ? 1 cos    2 2 1  cos  sin  sin  1 cos2   sin  sin2  cos2  1  cos  ? 1 2cos     1  cos  sin2  sin2  sin2  1  cos  ? 1  2 cos   cos2   1  cos  sin2  1  cos  ? (1  cos )(1  cos )  1  cos  1  cos2  1  cos  ? (1  cos )(1  cos )  1  cos  (1  cos )(1  cos ) 1  cos  1  cos   1  cos  1  cos 

17. ?

cot  csc  

cos  ? sin 

cot  csc  

cot  csc 

cot  csc 

18.

cot   csc  sin   tan 

?

sin   cos  

1

 sin 

1 ?

sin   cos  

sin  sin   cos  cos   1 sin  ?  sin  cos   sin  cos  cos   1 sin  ?  sin  (cos   1) cos  ?

cot  csc  

?

cot  csc  

1  tan  sec 

sin   cos 

sin 

 cos 

1 cos  sin   cos  cos  ?  1 cos  ?

sin   cos  

sin   cos  cos 

 cos 

sin   cos   sin   cos 

cos   1  sin  cos  sin (cos   1) cos  sin 



1 sin 

cot  csc   cot  csc  ©Glencoe/McGraw-Hill

391

Algebra 2

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19.

sec  sin  1 cos  sin 

7/24/02



sin  cos 

2:04 PM

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?

 cot 

sin  1  cos  ?   2csc  1  cos  sin  sin  sin  1  cos  1  cos  ?     2csc  sin  1  cos  1  cos  sin 

20.

sin  ?

 cos   cot 

1 sin  cos 



sin2  sin  cos  1  sin2  sin  cos  cos2  sin  cos  cos  sin 

1  2cos   cos2  ? sin2    2csc  sin (1  cos ) sin  (1  cos )

?

sin2   cos2   1  2cos  ?  2csc  sin (1  cos )

?

2  2cos  ?  2csc  sin (1  cos )

 cot   cot 

2(1  cos ) ?  2csc  sin (1  cos )

?

 cot 

2 ?  2csc  sin 

?

 cot 

?

2csc   2csc 

cot   cot 

21.

23.

1  sin  sin  1  sin  sin  1  sin  sin  1  sin  sin  1  sin  sin  1  sin  sin  1  sin  sin  1 sec2 

?

 ?

 ?

 ?



cot2  csc   1 cot2  csc   1  csc   1 csc   1 cot2 (csc   1) csc2   1 cot2  (csc   1) cot2 

1

?

?

 

sin   cos  cos 

1 sin   sin  sin  1  sin  sin  1

csc2 

?



sin 

 cos 

?



sin  cos  sin  cos 

cos  sin  sin   cos  cos  ? sin   cos  sin   cos  sin 

1

 csc   1



?

24. 1 

?

1

1

cos2   sin2   1 11

1 1 1 1

©Glencoe/McGraw-Hill

1  tan  1  cot 

22.

392





sin  sin   cos  sin  cos 

?



1 cos  1 cos  1 cos 



1 cos  1 cos 

 sec   1

?

 ?





sin  cos  sin  cos 

tan2  sec   1 tan2  sec   1  sec   1 sec   1 tan2 (sec   1) sec 2   1 2 tan (sec   1)

1 cos  ?

?



tan2 

?

1

1 cos 

Algebra 2

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25. 1  tan4 

26.

?

cos4   sin4   cos2   sin2  (cos2   sin2 )(cos2   sin2 )

?

 cos2   sin2  (cos2   sin2 )  1

?

 cos2   sin2  cos2   sin2   cos2   sin2 

?

 2 sec2   sec4  (1  tan2 )(1  tan2 )

?

 sec2 (2  sec2 ) [1  (sec2   1)](sec2 )

?

 (2  sec2 )(sec2 ) (2  sec2 )(sec2 )  (2  sec2 )(sec2 ) 1  cos  sin 



1  cos  1  cos 



27. 1  cos  sin 



1  cos2  sin  (1  cos ) sin2  sin  (1  cos ) sin  1  cos 

29.

?

?

?

 ?

 

sin  1  cos 

cos  ? cos    2sec  1  sin  1  sin  1  sin  cos  1  sin  ? cos      2sec  1  sin  1  sin  1  sin  1  sin 

28.

sin  1  cos 

cos 11  sin 2  cos 11  sin 2 11  sin 211  sin 2

sin  1  cos 

cos   sin  cos   cos   sin  cos  ?  2 sec  1  sin 2  2cos  ?  2sec  cos2  2 ?  2sec  cos2  2sec   2sec 

sin  1  cos  sin  1  cos  ?

tan  sin  cos  csc2   1 sin  cos 

 sin   cos  

1 2

sin2  1  cos 

30.

sin2  1  cos   1  cos  1  cos  sin2  (1  cos ) 1  cos2  sin2 (1  cos )

?

sin 

?

 2sec 

1

11

sin2 

?

 1  cos  ?

 1  cos  ?

 1  cos  ?

 1  cos 

1  cos   1  cos  31.

v 02

tan2 

2g sec2 

  

©Glencoe/McGraw-Hill

sin2  cos2  1 2g cos2 

v 02

v 02



sin2  cos2 

2g v 20 sin2 

32. 598.7 m



cos 2  1

2g

393

Algebra 2

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34. Sample answer: Trigonometric identities are verified in a similar manner to proving theorems in geometry before using them. Answers should include the following. • The expressions have not yet been shown to be equal, so you could not use the properties of equality on them. • To show two expressions you must transform one, or both independently. • Graphing two expressions could result in identical graphs for a set interval, that are different elsewhere.

33. Sample answer: Consider a right triangle ABC with right angle at C. If an angle A has a sine of x, then angle B must have a cosine of x. Since A and B are both in a right triangle and neither is the right angle, their sum  2

must be .

35. D

36. B

37.

38.

[360, 360] scl: 90 by [5, 5] scl: 1

[360, 360] scl: 90 by [5, 5] scl: 1

is not

may be 40.

39.

[360, 360] scl: 90 by [5, 5] scl: 1

[360, 360] scl: 90 by [5, 5] scl: 1

may be

may be

©Glencoe/McGraw-Hill

394

Algebra 2

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41.

42.

[360, 360] scl: 90 by [5, 5] scl: 1

[360, 360] scl: 90 by [5, 5] scl: 1

may be

is not

43.

25 2

44. 

25 3

45.

2193 12

46. 

27 4

48. 1: 360; 45

47. 1: 360; 30 y 5 4 3 2 1

y 5 4 3 2 1

y  cos (  30˚)

O

270˚ 180˚ 90˚ 2 3 4 5

90˚ 180˚ 270˚



O

270˚ 180˚ 90˚ 2 3 4 5

 2

49. 3; 2; 

50.

5 6

52.

22 4

54.

2  23 4

y  sin (  45˚)  90˚ 180˚ 270˚

y 5 4 3 2 1 

3 2

51.

26 4

53.

26 4

O    2 2 3 4 5



(



y  3 cos   2

 2



3 2

)



22 2

©Glencoe/McGraw-Hill

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Sum and Difference of Angles Formulas Pages 788–790 2. Use the formula sin(  )  sin  cos   cos  sin . Since sin 105  sin(60  45), replace  with 60 and  with 45 to get sin 60 cos 45  cos 60 sin 45. By finding the sum of the products of the values,

1. sin (  )  sin   sin  sin  cos   cos  sin   sin   

the result is

26  22 4

or about 0.9659. 3. Sometimes; sample answer: The cosine function can equal 1.

4.

26  22 4

5.

26  22 4

6.

22  26 4

7.

23 2

8.

23 2

1 2

10. cos (270  )

9. 

?

 cos 270 cos   sin 270 sin  ?

 0  (1 sin )  sin   2

sin a  b  cos 

11. sin  cos

 2

 cos  sin

 2

?

12.

sin(  30)  cos(  60)

?

 sin  cos 30  cos  cos 30  cos  cos 60  sin  sin 60

?

 cos 

?



?

sin   0  cos   1  cos  cos   cos 

23 sin  2

1 cos 2 ?



1 2

 cos  

23 sin 2

1 2



1 2

 cos   cos   cos 

13.

5  23 1  5 23

©Glencoe/McGraw-Hill

14.

396

22 2

Algebra 2

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15.

22  26 4

16.

 26  22 4

17.

 26  22 4

18.

 26  22 4

19.

 26  22 4

20. 

21. 

22 2

22.

22 2

22  26 4 23 2

23.

22 2

24. 

25.

22  26 4

26.

27.

 26  22 4

28. sin (270  )

22 2

?

 sin 270 cos   cos 270 sin  ?

 1 cos   0  cos  30. cos (90  )

29. cos (90  )

?

?

 cos 90 cos   sin 90 sin 

?

 0  cos   1  sin   sin 

 cos 90 cos   sin 90 sin 

?

 0  1 sin   sin  31.

?

sin(90  )  cos  sin 90 cos   cos 90 sin 

32.

sin  cos

?

 cos 

3 2

3 2 2

?

 cos 

 cos  sin

3 2

?

?

 cos 

?

sin   0  cos (1)  cos 

1  cos   0  sin   cos 

?

cos   0  cos 

?

0  (cos )  cos 

cos   cos 

©Glencoe/McGraw-Hill

sin 1 

cos   cos 

397

Algebra 2

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33.

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Page 398 TF06 Manish 06:BOOKS:PRD:PQ245_64575F FINAL DELIVERY:PQ245-14:

?

cos (  )  cos  cos  cos   sin  sin 

34.

?

cos(2  )  cos  cos 2 cos   [sin 2 sin ]

?

 cos 

?

 cos 

?

1  cos   0  sin   cos  cos   cos 

?

1  cos   [0  sin ]  cos  ?

1  cos   0  cos  cos   cos  ?

36. sin (60  )  sin (60  )

sin(  )  sin 

35.

?

 sin 60 cos   cos 60 sin   sin 60 cos   cos 60 sin 

?

sin  cos   [cos  sin ]  sin  ?

0  cos   [1  sin ]  sin 

?



?

0  [sin ]  sin  sin   sin 

23 2

23 2

cos  

cos  

1 2

1 2

sin  

sin 

 23 cos   3

 6

37. sin a  b  cos a  b ?

 3  cos 6

38. sin (   ) sin (   )  sin2   sin2 

 3  sin 6

 sin  cos  cos  sin  cos 

 sin 

23 sin   cos 2 1 cos   sin  2 1 ? 1  sin   sin  2 2 1  2 ?



?

 (sin  cos   cos  sin ) (sin  cos   cos  sin ) ?

23 2

 sin2  cos2   cos2  sin2  ?

 sin2 (1  sin2 )  (1  sin2 ) sin2  ?

 sin2   sin2  sin2  

 sin 

sin2   sin2  sin2   sin2   sin2 

©Glencoe/McGraw-Hill

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Algebra 2

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39.

y

40. ?

cos (  )  ?

cos (  ) 

4

1  tan  tan  sec  sec  1

sin 

y  10 sin (2t  30°)  10 cos (2t  60°)

sin 

 cos   cos  1 cos 



180° 90°

1 cos 

cos (  )  sin 

1 cos 



sin  cos 

1 cos 



90°

180° t

2 4

?

1  cos  

O

cos  cos  cos  cos 

?

cos (  )  cos  cos   sin  sin  1

cos (  )  cos (  ) 41. Destructive; the resulting graph has a smaller amplitude than the two initial graphs.

42. 0.3681 E

43. 0.4179 E

44. 0.6157 E

45. 0.5563 E

46. tan (  )  

©Glencoe/McGraw-Hill

399

sin(  ) cos(  ) sin  cos   cos  sin  cos  cos   sin  sin



sin  cos  cos  cos  cos  cos  cos  cos 

cos  sin 



tan   tan  1  tan  tan 

 cos  cos  sin  sin 

 cos  cos 

Algebra 2

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tan (  )  

sin(  ) cos(  ) sin  cos   cos  sin  cos  cos   sin  sin 



sin  cos  cos  cos  cos  cos  cos  cos 

cos  sin 



tan   tan  1  tan  tan 

 cos  cos 

47. Sample answer: To determine communication interference, you need to determine the sine or cosine of the sum or difference of two angles. Answers should include the following information. • Interference occurs when waves pass through the same space at the same time. When the combined waves have a greater amplitude, constructive interference results and when the combined waves have a smaller amplitude, destructive interference results.

48. A

49. C

50. cot   sec  ?

 ?

 ?



sin  sin 

 cos  cos 

cos2   sin  sin  cos  cos2  sin   sin  cos  sin  cos  cos  sin 



1 cos 

 cot   sec 

©Glencoe/McGraw-Hill

400

Algebra 2

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51. sin2   tan2 

52.

?

 (1  cos2 )  ?

 sin2   ?

 sin2   ?

 sin2  

sec2  csc2  1 cos2  sin2  cos2 

 csc 

sec2

?

sin  (sin   csc )  2  cos2 

2

?

sin2   1  2  cos2 

?

1  cos2   1  2  cos2  2  cos2   2  cos2 

1 sin2 

 sin2   tan2  53. 1

cos  1  cos 

sec  tan  sin  cos  cos  sin  1 sin 

?

 csc 

54. 1

?

 csc  ?

 csc  ?

 csc 

csc   csc  55. 4

56. sec 

57. 2 sec 

58. sin   

3 234 , 34

cos  

5 234 , 34

csc    sec   59.

4 5

3 5

sin    , cos    , 4 3

5 3

234 , 5

5 4 3 4

61. 360

62. 3,991,680

63. 56

64. 210

65. about 228 mi

66.

2 25 2

5 3

cot   

y2 34



x2 6

1

3 5

67.

©Glencoe/McGraw-Hill

234 , 3

60. sin   1, cos   0, tan   undefined, csc   1, sec   undefined, cot   0

tan   , csc    , sec    , cot  

3 5

tan    ,

68. 401

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3 4

69.

25 5

70.

71.

26 2

72.

73.

3 25 5

2 16 12 2

74.

Lesson 14-6

222 12 2

Double-Angle and Half-Angle Formulas Pages 794–797

1. Sample answer: If x is in the x third quadrant, then is 2 between 90 and 135. Use the half-angle formula for cosine knowing that the value is negative.

2. Sample answer: 45; cos 2(45)  cos 90 or 0,

3. Sample answer: The identity used for cos 2 depends on whether you know the value of sin , cos , or both values.

4.

24 , 25

6.

23 1 22  13 , , , 2 2 2

5.

4 25 , 9

1 230 , 9 6

 ,



2 cos 45  2 

26 6

12 2

or 22

7 25 2 25 , 25 5 5

 ,

22  13 2 3 27 , 8

7. 

1 8

 ,

28  2 17 , 4

9.

8.  

22  13 2

28  2 17 4

22  13 2

?

sin 2x 1  cos 2x

?

2 sin x cos x 1  (1  2 sin2 x)

?

2 sin x cos x 2 sin2 x

?

cos x sin x

10. cot x    

 cot x ©Glencoe/McGraw-Hill

402

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?

11. cos2 2x  4 sin2 x cos2 x  1

12. 1.64

?

cos2 2x  sin2 2x  1 11 120 119 5 226 226 , , , 169 169 26 26

4 26 , 25

13.  15.

4 22 , 9

7 26 , 9 3

 ,



23 3

16.

3 255 23 28  155 , , , 32 32 4

17.   19.

24 7 3 210 , , , 25 25 10

18. 

17 215 221 , 18 6 6

 ,

4 22 7 23 16  4 13 , , 9 9 6

21. 

23.

 ,

215 , 8





215 5

210 10

7 210 26 , 8 4 4

 ,

28  155 4

235 , 18



23 210 , 25 5

14. 

20.

120 119 5 226 , , , 169 169 26

22.

215 7 , , 8 8

23 16  4 13 6

4 25 , 9



1 26 230 , 9 6 6





226 26

28  2 115 , 4

28  2 115 4

4 221 17 , , 5 25

 ,

24. 

25 110  1210 , 10 25 110  1210 10

25. 

22  13 2

26.

27. 

22  12 2

28. 

22  13 2

30. 

22  13 2

29. 31.

22  12 2 ?

sin 2x  2 cot x sin2 x cos x ? 2 sin x cos x  2  sin2 x sin x 2 sin x cos x  2 sin x cos x

22  12 2

2 cos2

32. 2a

3

x 2

?

 1  cos x

2

1  cos x b 2

1  cos x b 2

2a

?

 1  cos x ?

 1  cos x

1  cos x  1  cos x

©Glencoe/McGraw-Hill

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?

1 2

?

1 2

?

1 2

34. sin2 x  (1  cos2 x)

33. ?

sin4 x  cos4 x  2 sin2 x  1 (sin2 x  cos2 x)(sin2 x  cos2 x)

sin2 x  [1  (1  2 sin2 x)]

?

 2 sin2 x  1 (sin2 x  cos2 x)  1

sin2 x  (2 sin2 x) sin2 x  sin2 x

?

 2 sin2 x  1 [sin2 x  (1  sin2 x)]  1 ?

 2 sin2 x  1 sin2 x  1  sin2 x ?

 2 sin2 x  1 2 sin2 x  1  2 sin2 x  1 tan2

35.

x 2

?



1  cos x 1  cos x

36.

x

sin2 2 cos a

3

a

3

2 x

?



1  cos x 1  cos x

2

1  cos x 2 b 2 ? 1  cos x 1  cos x 2 b 2

1  cos x 1  cos x





1 cos x  sin x cos x sin x 1  cos2 x sin x cos x sin2 x sin x cos x sin x cos x

?

 tan x ?

 tan x ?

 tan x

tan x  tan x

1  cos x 1  cos x 1  cos x

1 37. 46.3

38. 1

39. 2  23

40.

2 g

3

1  cos L 1  cos L



?

2 g

v 2 tan (1  sin2 )

?

2 g

v 2 tan  cos2 

?

2 2 v sin g v 2 sin 2 g

  404

3

1  cos L 1  cos L

v 2 (tan   tan  sin2 )



©Glencoe/McGraw-Hill

?

 tan x

 cos 

Algebra 2

Chapter 14

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41.

1 tan 4

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y

42. 2.5 2 1.5 1 0.5 

3  2



2

y  sin2 x

x

O



 2

1

1 1.5 y   2 cos 2x 2

3 2

y  cos2 x

2.5

Sample answer: They all have the same shape and are vertical translations of each other.  2

43. The maxima occur at x  and

3 . The 2

44.

y 2.5 2 1.5 1 0.5

minima occur

at x  0,  and 2.

270˚ 180˚ 90˚ 1 1.5 2 2.5

y  sin 2x

x O

90˚ 180˚ 270˚

45. The graph of f(x) crosses the x-axis at the points specified in Exercise 41.

46. c  1 and d  0.5

47. Sample answer: The sound waves associated with music can be modeled using trigonometric functions. Answers should include the following information. • In moving from one harmonic to the next, the number of vibrations that appear as sine waves increase by 1.

48. D

©Glencoe/McGraw-Hill

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• The period of the function as you move from the nth harmonic to the (n  1)th harmonic decreases from 2 2 . to n1

n

51.

26  22 4

53.  55.

26  22 4

50.

49. B

52. 

23 2

26  22 4

54.

1 2

22 2

56. ?

cot2   sin2  

cos2  csc2   sin2  sin2  csc2  1

?

cot   sin   2

2

cos2  sin2   sin2  1

sin2  sin2 

cot2   sin2  1 cot2   sin2   cot2   sin2  ?

cot2   sin2  

57. cos (cos   cot )

58. 101 or 10

?

 cot  cos 1sin   12 ?



cos  cos  sin   cot  cos  sin 

?

 cos2   cot  cos   cos (cos   cot ) 59. 102.5 or about 316 times greater

60. 6, 5

61. 1, 1

62. 0, 2

63.

5 , 2

1 1 2 2

64.  ,

2 1 2

65. 0, 

©Glencoe/McGraw-Hill

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Chapter 14 Practice Quiz 2 Page 797 ?

1. sin  sec   tan  sin  

1  cos sin  cos 

?

2.

sec   cos   sin  tan  cos  ? 1  cos    sin  tan  cos  cos  cos2  ? 1   sin  tan  cos  cos  1  cos2  ?  sin  tan  cos  sin2  ?  sin  tan  cos  sin  ?  sin  tan  sin  cos  sin  tan   sin  tan 

4.

sin (90  )  cos 

?

 tan  ?

 tan  ?

tan   tan 

sin (cos   1) cos  sin  cos   sin  ? sin   tan   cos  sin  ? sin  cos  sin   tan    cos cos  sin   tan   sin   tan 

? 3. sin   tan  

?

sin 90 cos   cos 90 sin   cos  ?

cos   0  cos  cos   cos 

3 ?  b  sin  2 3 3 ? cos cos   sin sin   sin  2 2 cos a

5.

?

6. sin (  30)  cos (  60) ?

 (sin  cos 30  cos  sin 30)  (cos  cos 60  sin  sin 60)

?

0  (1  sin )  sin 

a ?

sin   sin 

13 2

sin  

1 a cos 2 ?



1 2

1 2

cos b 

13 2

sin b

1 2

 cos   cos   cos  7.

23 2

9.

22  13 2

©Glencoe/McGraw-Hill

9 282 82

8.  10.

407

22  12 2

Algebra 2

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Lesson 14-7

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Solving Trigonometric Equations Pages 802–804

1. Sample answer: If sec   0 1 then  0. Since no value cos 

of  makes

1 cos 

2. Sample answer: The function is periodic with two solutions in each of its infinite number of periods.

 0. there

are no solutions. 3. Sample answer: sin   2

4. 60, 120, 240, 300

5. 135, 225

6.

7.

 6

  5 3 , , , 6 2 6 2

8. 0 

9. 0  k

2k 3

10. 90  k  360, 180  k  360

11. 60  k  360, 300  k  360

12.

7 6

11 6

 2k,

 2k or

210  k  360, 330  k  360 13.

 6

 2k,

5 6

 2k,

 2

 2k

14. 31.3

or 30  k  360, 150  360, 90  k  360 15. 60, 300

16. 240, 300

17. 210, 330

18. 30, 150, 210, 330

19.

 5 3 , , 6 6 2

20.

 2

21.

7 11 , 6 6

22.

 3 2 4 , , , 2 2 3 3

23.

 3

 2k,

5 3

 2k

24.   2k, 5 3

25.

2 3

27.

 3

 2k,

 2k,

©Glencoe/McGraw-Hill

4 3

5 3

 2k

 3

 2k,

 2k

26. 0  2k

 2k

28. 0  k, 408

 6

 2k,

5 6

 2k

Algebra 2

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29. 45  k  180

30. 0  k  180

31. 270  k  360

32. 30  k  360, 150  k  360

33. 0  k  180, 60  k  180

34. 120  k  360, 240  k  360

 3  2k,  2k 2 2

35. 0  2k,

36.

7 6

 2k,

11 6

 2k or

210  k  360, 330  k  360

or 0  k  360, 90  k  360, 270  k  360 37. 0  k or 0  k  180

38.

 2

 k,

2 3

 2k,

4 3

 2k

or 90  k  180, 120  k  360, 240  k  360 39. 0  2k,

 3

 2k,

5 3

 2,

40.

 2

 4k or 90  k  720

or 0  k  360, 60  k  360, 300  k  360 41. S 

352 tan 

43. y 

3 2



or S  352 cot 

3 2

42. about 32 44. 10

sin (t)

y 4 3.5 3 2.5 2 1.5 1 0.5 O 1 1

3

3

y  2  2 sin ( t )

1 2 3 4 5 6 7 8 9

t

45. (4.964, 0.598)

©Glencoe/McGraw-Hill

46. Sample answer: Temperatures are cyclic and can be modeled by trigonometric functions. Answers should include the following information.

409

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• A temperature could occur twice in a given period such as when the temperature rises in the spring and falls in autumn. 47. D

48. B

49.

24 7 210 3 210 , , , 25 25 10 10

50.

1 1 23 23 , , , 2 2 2 2

51.

5 211 7 23 233 , , , 18 18 6 6

52.

7 25 2 25 24 , , , 25 25 5 5

54.

22 2

53. 

23 2

55. b  11.0, c  12.2, mC  78

©Glencoe/McGraw-Hill

410

Algebra 2

Chapter 14

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