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Hou
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d.Precalculus with Limits, Answers to Section 2.1 1
Chapter 2Section 2.1 (page 134)
Vocabulary Check (page 134)1. nonnegative integer; real 2. quadratic; parabola3. axis 4. positive; minimum5. negative; maximum
1. g 2. c 3. b 4. h5. f 6. a 7. e 8. d
Vertical shrink Vertical shrink and reflection in the x-axis
Vertical stretch Vertical stretch and reflection in the x-axis
Vertical shift Vertical shift
Vertical shift Vertical shift
Horizontal shift Horizontal shrink andvertical shift
Horizontal stretch and Horizontal shiftvertical shift
Horizontal shift, Horizontal shift,vertical shrink, reflection vertical shrink, and in the x-axis, and vertical vertical shiftshift
Reflection in the axis, Horizontal shift,vertical shrink, horizontal vertical stretch, andshift, and vertical shift vertical shift
x-
y
x
2
1
−1
3
4
7
1−1−2−3−4 2 3 4
x−4
−4
−6
−8
−6−8
2
4
42 6
6
y
y
x−4−6−8 2 6 8
−4
−6
4
6
8
10
−6 −4 −2 2 6 8 10
4
6
8
x
y
−8 −6 −4 −2 2 4
2
8
10
x
−2
yy
x−6
−4
−2
2
4
6
8
−2 2 6
y
x−3 −2 −1
−11
3
4
5
2 3−2 −1 1 2 3 4−1
3
4
5
x
y
−6 –4 4 6
−4
4
6
8
x
y
−6 −4 −2 2 4 6−2
6
8
10
x
y
−3 −2 2 3
−2
1
2
3
4
x
y
−3 −2 −1 1 2 3−1
2
3
4
5
x
y
−6 −4 −2 2 4 6
4
2
6
x
y
−3 −2 −1 1 2 3−1
1
2
3
4
5
x
y
−6 −4 4 6
−6
−4
−2
2
4
6
x
y
−3 −2 −1 1 2 3−1
1
2
3
4
5
x
y9. (a)
10. (a) (b)
(d)(c)
(b)
(c) (d)
11. (a) (b)
(c) (d)
12. (a) (b)
(c) (d)
333202CB02_AN.qxd 1/1/70 09:36 AM Page 1
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d.
Precalculus with Limits, Answers to Section 2.1 2
(Continued)
13. 14.
Vertex: Vertex:Axis of symmetry: y-axis Axis of symmetry:x-intercepts: x-intercepts:
15. 16.
Vertex: Vertex:Axis of symmetry: y-axis Axis of symmetry:x-intercepts: x-intercepts:
17. 18.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:x-intercepts: No x-intercept
19. 20.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:x-intercept: x-intercept:
21. 22.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:
No x-intercept x-intercepts:
23. 24.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:x-intercepts: x-intercepts:
25. 26.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:No x-intercept No x-intercept
27. 28.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:x-intercepts: x-intercepts: �3, 0�, �6, 0���4, 0�, �12, 0�
x �92x � 4
�92, 34��4, �16�
x4 6−2
2
8 10−2
−4
−6
y
−12
−16
−20
−8
4
4 8 16x
y
x �14x �
12
�14, 78�� 1
2, 20�−1−2−3 1 2 3
1
3
4
5
6
x
y
−4−8 4 8
10
20
x
y
��2 ± �5, 0��1 ± �6, 0�x � �2x � 1
��2, 5��1, 6�
−6 −5 −3 −2 −1 1 2
−3
−2
1
2
4
5
x
y
−4 2 6
−4
−2
6
x
y
��32 ± �2, 0�
x � �32x �
12
��32, �2�� 1
2, 1�
−5 −4 −3 −2 −1 1 2
−3
−2
1
2
3
4
x
y
−2 −1 1 2 3
1
3
4
5
x
y
��1, 0��4, 0�x � �1x � 4
��1, 0��4, 0�−4 −3 −2 −1 1 2
1
2
3
4
5
6
x
y
−4 4 8 12 16
4
8
12
16
20
x
y
��5 ± �6, 0�x � 6x � �5
�6, 3���5, �6�−10−20 10 20 30
10
20
30
40
50
x
y
−20 −12 4 8
−8
12
16
20
x
y
�±8, 0��±2�2, 0�x � 0
�0, 16��0, �4�
x
12
3 6 9
18
−3
3
6
9
−3−6−9
y
−4 −3 −1 1 2 3 4
−5
−3
−2
1
2
3
x
y
�±5, 0��±�5, 0�x � 0
�0, 25��0, �5�
−10−20 10 20
30
x
y
−4 −3 −1 1 3 4
−6
−3
−2
1
2
x
y
333202CB02_AN.qxd 1/1/70 09:36 AM Page 2
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d.Precalculus with Limits, Answers to Section 2.1 3
(Continued)
29. Vertex:Axis of symmetry:x-intercepts:
30. Vertex:Axis of symmetry:x-intercepts:
31. Vertex:Axis of symmetry:x-intercepts:
32. Vertex:Axis of symmetry:x-intercepts:
33. Vertex:Axis of symmetry:x-intercepts:
34. Vertex:Axis of symmetry:No x-intercept
35. Vertex:Axis of symmetry:x-intercepts:
36. Vertex:Axis of symmetry:x-intercepts:
37. 38.
39. 40.
41. 42.
43. 44.
45. 46.
47. 48.
49. 50.
51. 52.
53. 54. 55.
56.
57. 58.
59. 60.
61. 62.
63. 64.
65. 66.
67. 68.
69. 70.
71. 55, 55 72. 73. 12, 6 74. 21, 7S
2,
S
2
g�x� � �2x2 � x � 10g�x� � �2x2 � 7x � 3
f �x� � 2x 2 � x � 10f �x� � 2x 2 � 7x � 3
g�x� � �x 2 � 12x � 32g�x� � �x2 � 10x
f �x� � x 2 � 12x � 32f �x� � x2 � 10x
g�x� � �x 2 � 25g�x� � �x2 � 2x � 3
f �x� � x2 � 25f �x� � x2 � 2x � 3
��15, 0�, �3, 0��7, 0�, ��1, 0�
−18 4
−60
10
−10
−6
14
10
��7, 0�, �34, 0���5
2, 0�, �6, 0�
−9 2
−70
10
−5
−40
10
10
��2, 0�, �10, 0��3, 0�, �6, 0�
−4 12
−40
10
−8
−4
16
12
�0, 0�, �5, 0��0, 0�, �4, 0�
−1 6
−6
14
−4 8
−4
4
��3, 0�, �12, 0�
�5, 0�, ��1, 0��3, 0��±4, 0�
f �x� � �450�x � 6�2 � 6f �x� � �163 �x �
52�2
f �x� �1981�x �
52�2
�34f �x� � �
2449�x �
14�2
�32
f �x� � 2�x � 2� 2 � 2f �x� �34�x � 5�2 � 12
f �x� � �14�x � 2�2 � 3f �x� � �
12�x � 3�2 � 4
f �x� � �x � 4� 2 � 1f �x� � �x � 2�2 � 5
y � 2�x � 2� 2y � �2�x � 2�2 � 2
y � �x � 2� 2 � 1y � ��x � 1�2 � 4
y � �x 2 � 1y � �x � 1� 2
��3 ± �14, 0�x � �3
��3, �425 �
−14 10
−10
6
��2 ± �6, 0�x � �2
��2, �3�
−8 4
4
−4
x � 3�3, �5�
0 6
−20
0
�4 ± 12�2, 0�x � 4
�4, �1�
−6 12
−12
48
��5 ± �11, 0�x � �5
��5, �11�−20 10
−15
5
��4 ± �5, 0�x � �4
��4, �5�
−18 12
−6
14
��6, 0�, �5, 0�x � �
12
��12, 121
4 �−10 10
−80
35
�1, 0�, ��3, 0�x � �1
��1, 4�
−8 7
−5
5
333202CB02_AN.qxd 1/1/70 09:36 AM Page 3
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d.
Precalculus with Limits, Answers to Section 2.1 4
(Continued)
75. (a)
(b)
(c)
(d) (e) They are identical.
76. (a) (b)
(c)
77. 16 feet
78. (a) 1.5 feet (b)(c) feet
79. 20 fixtures 80. 1222 units 81. 350,000 units
82. $2000
83. (a) $14,000,000; $14,375,000; $13,500,000(b) 24; $14,400
84. (a) $408; $468; $432(b) $6.25 per pet; $468.75
Answers will vary.
85. (a)
(b) 4299; answers will vary.(c) 8879; 24
86. (a) and (c)
(b) (d) 1995(e) Answers will vary. (f)
87. (a) (b) 69.6 miles per hour
88. (a) and (c)
(b)(d) 45.5 miles per hour
89. True. The equation has no real solutions, so the graph hasno -intercepts.
90. True. The vertex of is and the vertex of is
91.
92. Conditions (a) and (d) are preferable because profitswould be increasing.
93. Yes. A graph of a quadratic equation whose vertex is onthe x-axis has only one x-intercept.
94. Answers will vary. 95.
96. 97.
98. 99. 27 100. 7
101. 102. 103. 109
104. 72 105. Answers will vary.
�43�
140849
y � �3x � 20
y �54 x � 3y �
32 x �
134
y � �13 x �
53
f �x� � a�x �b
2a�2
�4ac � b2
4a
��54, �71
4 �.g�x���5
4, 534 �f �x�
x
y � �0.0082x2 � 0.746x � 13.47
10 8020
31
0
−5
100
25
�1,381,000y � 4.30x2 � 49.9x � 886
4650
12
950
00
43
5000
�228.64
665764 feet � 104.02 feet
x � 50 meters, y �100�
metersA � x�200 � 2x
� �;
y �200 � 2x
�r �
1
2y; d � y�
A � �83 �x � 25�2 �
50003
x � 25 feet, y � 33 13 feet
00
60
2000
x � 25 feet, y � 33 13 feet
A �8x�50 � x�
3
x 5 10 15 20 25 30
A 600 1067 1400 1600 1667 1600
333202CB02_AN.qxd 1/1/70 09:36 AM Page 4
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d.Precalculus with Limits, Answers to Section 2.2 5
Section 2.2 (page 148)
Vocabulary Check (page 148)1. continuous 2. Leading Coefficient Test3. ; 4. (a) solution; (b) (c) x-intercept5. touches; crosses 6. standard7. Intermediate Value
1. c 2. g 3. h 4. f5. a 6. e 7. d 8. b
−4 −3 −2 2 3 4
−4
−3
−2
−1
2
3
4
x
y
−4 −3 −2 2 3 4
1
2
3
4
x
y
−5 −4 −2 1 2 3
−4
x
y
−4 −3 −2 2 3 4
−4
−3
−2
−1
1
2
3
4
x
y
y
x−4 −3 −1 1
6
5
4
3
2
1
−13 4
y
x−4 −3 −2 −1
−1
−2
1
6
5
2 3 4
−4 −3 −2 −1 1 2 3 4
−2
x
y
−4 −3 −2 1 2 3 4
−2
1
2
3
5
6
x
−1
y
−4 −3 −2 2 3 4
−4
1
2
3
4
x
y
−5 −4 −3 −2 −1 1 2 3
−2
1
2
3
4
5
6
x
y
−5 −4 −3 −2 1 2 3
−4
−3
1
2
3
4
x
y
−4 −3 −2 2 3 4
−4
−3
2
3
4
x
y
−4 −3 −2 1 2 3 4
−4
−3
2
3
4
x
y
−4 −3 1 2 3 4
−4
−3
1
2
3
4
x
y
−3 −2 1 2 4 5
−5
−4
−3
−2
1
2
3
x
y
−4 −3 −2 2 3 4
−4
−3
−2
1
2
3
4
x
y
−4 −3 −2 2 3 4
−5
−4
1
2
3
x
y
−3 −2 2 3 4 5
−4
−3
−2
1
2
3
4
x
y
�x � a�;n � 1n
9. (a) (b)
(c) (d)
10. (a) (b)
(c) (d)
11. (a) (b)
(c) (d)
(e) (f)
12. (a) (b)
(c) (d)
333202CB02_AN.qxd 1/1/70 09:36 AM Page 5
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d.
Precalculus with Limits, Answers to Section 2.2 6
(Continued)
13. Falls to the left, rises to the right14. Rises to the left, rises to the right15. Falls to the left, falls to the right16. Falls to the left, falls to the right17. Rises to the left, falls to the right18. Falls to the left, rises to the right19. Rises to the left, falls to the right20. Rises to the left, rises to the right21. Falls to the left, falls to the right22. Rises to the left, falls to the right23. 24.
25. 26.
27. (a)(b) odd multiplicity; number of turning points: 1(c)
28. (a)(b) odd multiplicity; number of turning points: 1(c)
29. (a) 3(b) even multiplicity; number of turning points: 1(c)
30. (a)(b) even multiplicity; number of turning points: 1(c)
31. (a)(b) odd multiplicity; number of turning points: 1(c)
32. (a)
(b) odd multiplicity; number of turning points: 1(c)
33. (a)(b) odd multiplicity; number of turning points: 2(c)
34. (a)(b) odd multiplicity; number of turning points: 2(c)
−6
−16
6
16
0, 1 ±�2
−6
−24
6
8
0, 2 ± �3
−8
−5
4
3
�5 ± �37
2
−6
−4
6
4
�2, 1
−25
−5
15
25
�5
−18
−20
18
4
−30
−5
30
55
±7
−30
−30
30
10
±5
−6 6
−3
g
f
5
−8
−20
8
g
f
12
−6
gf
6
−9 9
−8
−4 4
8
fg
y
x−4 −3 −2
−2
−1−1 1 2 3 4
y
x
−4
2−2−6−8 6 8
(e) (f)
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d.Precalculus with Limits, Answers to Section 2.2 7
(Continued)
35. (a) 0, 2(b) 0, odd multiplicity; 2, even multiplicity; number of
turning points: 2(c)
36. (a)(b) odd multiplicity; 0, even multiplicity; number
of turning points: 3(c)
37. (a)(b) 0, odd multiplicity; even multiplicity; number
of turning points: 4(c)
38. (a)(b) odd multiplicity; number of turning points: 2(c)
39. (a) No real zeros(b) number of turning points: 1(c)
40. (a)(b) odd multiplicity; number of turning points: 3(c)
41. (a)(b) odd multiplicity; number of turning points: 2(c)
42. (a)(b) odd multiplicity; number of turning points: 2(c)
43. (a)
(b) -intercepts: (c)(d) The answers in part (c) match the -intercepts.
44. (a)
(b) x-intercepts:(c)(d) The answers in part (c) match the x-intercepts.
45. (a)
(b) -intercepts:(c)(d) The answers in part (c) match the -intercepts.
46. (a)
(b) (c)(d) The answers in part (c) match the x-intercepts.
47. 48.
49. 50.
51. 52. f �x� � x3 � 7x 2 � 10xf �x� � x3 � 5x2 � 6x
f �x� � x 2 � x � 20f �x� � x2 � 4x � 12
f �x� � x2 � 3xf �x� � x2 � 10x
x � 0, 3, �3�0, 0�, �±3, 0�
−18 18
−12
12
xx � 0, 1, �1, 2, �2
�0, 0�, �±1, 0�, �±2, 0�x
−6 6
−4
4
x � �2, ��2, �1��2, 0�, ���2, 0�, ��1, 0�
−3
−11
3
2
xx � 0, 52�0, 0�, �5
2, 0�x
−2
−4
6
12
−9
−20
9
140
4, ±5
−8
−16
7
4
±2, �3
−6
−60
6
20
±�5
−4
−5
4
40
−9
−6
9
6
0, ±�2
−9
−6
9
6
±�3,0, ±�3
−6
−150
6
25
5, �4, 0,5, �4
−7
−5
8
5
333202CB02_AN.qxd 1/1/70 09:36 AM Page 7
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d.
Precalculus with Limits, Answers to Section 2.2 8
(Continued)
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67. (a) Falls to the left, rises to the right(b) (c) Answers will vary.(d)
68. (a) Rises to the left, rises to the right(b) (c) Answers will vary.(d)
69. (a) Rises to the left, rises to the right(b) No zeros (c) Answers will vary.(d)
70. (a) Falls to the left, falls to the right
(b) 2, 8 (c) Answers will vary.
(d)
71. (a) Falls to the left, rises to the right
(b) 0, 3 (c) Answers will vary.
(d)
72. (a) Rises to the left, falls to the right
(b) 1 (c) Answers will vary.
(d)
73. (a) Falls to the left, rises to the right
(b) 0, 2, 3 (c) Answers will vary.
(d)
x−1
2
1
41
(2, 0) (3, 0)(0, 0)
−2
−15 6−2−3
3
4
5
6
7
y
−2 −1 2
−1
2
3
x(1, 0)
y
−1 1 2 4
−4
−3
1
x(0, 0) (3, 0)
y
4 6 10
2
4
6
8
10
x(2, 0) (8, 0)
y
−4 −2 2 4
2
6
8
t
y
x−1−3−4
2
1
1 43
4
−4
(−2, 0) (0, 0) (2, 0)
3
y
0, ±2
x
−4
−8
−4−8−12
12
4
4
(−3, 0)
8 12
(3, 0)
(0, 0)
y
0, ±3
f �x� � x5 � 10x4 � 14x3 � 88x2 � 183x � 90
f �x� � x5 � 16x4 � 96x3 � 256x2 � 256x
f �x� � x4 � 4x3 � 23x2 � 54x � 72
f �x� � x4 � x3 � 15x2 � 23x � 10
f �x� � x3 � 27x2 � 243x � 729
f �x� � x3 � 3x
f �x� � x3 � 9x2 � 6x � 56
f �x� � x3 � 2x2 � 3x
f �x� � x2 � 12x � 32
f �x� � x2 � 4x � 4
f �x� � x3 � 10x2 � 27x � 22
f �x� � x2 � 2x � 2
f �x� � x5 � 5x3 � 4x
f �x� � x 4 � 4x3 � 9x2 � 36x
333202CB02_AN.qxd 1/1/70 09:36 AM Page 8
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d.Precalculus with Limits, Answers to Section 2.2 9
(Continued)
74. (a) Rises to the left, falls to the right(b) (c) Answers will vary.(d)
75. (a) Rises to the left, falls to the right(b) (c) Answers will vary.(d)
76. (a) Rises to the left, rises to the right(b) (c) Answers will vary.(d)
77. (a) Falls to the left, rises to the right(b) 0, 4 (c) Answers will vary.(d)
78. (a) Falls to the left, rises to the right(b) 0, 4 (c) Answers will vary.(d)
79. (a) Falls to the left, falls to the right(b) (c) Answers will vary.(d)
80. (a) Falls to the left, rises to the right(b) (c) Answers will vary.(d)
81. 82.
Zeros: Zeros:odd multiplicity odd multiplicity; 0,
even multiplicity83. 84.
Zeros: Zeros:even multiplicity; even multiplicity
odd multiplicity3, 92,
�2, 53,�1,
−12 12
−3
21
−12
−6
18
14
±2�2,0, ±2,
−9 9
−6
6
−9 9
−6
6
−6 −4 −2 4 6 8
2
4
6
x(−1, 0) (3, 0)
y
�1, 3
−3 −1 1 2 3
−6
−5
−2
−1
t(−2, 0) (2, 0)
y
±2
−4 −2 2 4 6 8 10 12
4
6
8
10
12
14
x(0, 0) (4, 0)
y
−4 −2 2 6 8
2
x(0, 0) (4, 0)
y
x(0, 0)
−300
2−2−6
100
(4, 0)
(−4, 0)
6
−200
y
0, ±4
x−10
(−5, 0) (0, 0)
−20
5 10−15
5
y
�5, 0
x41
(0, 0)
32−2−3−4
4
8
16
20
32
− , 0 (( 52, 0 ((
12
y
�32, 0, 52
333202CB02_AN.qxd 1/1/70 09:36 AM Page 9
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d.
Precalculus with Limits, Answers to Section 2.2 10
(Continued)
85.
86.
87.
88.
89. (a)
(b) Domain:(c)
6 inches 24 inches 24 inches(d)
90. (a) Answers will vary. (b) Domain:(c)
91. (a)(b)(c) inches(d)
When the volume is maximum at dimensions of gutter are 3 inches 6 inches3 inches
(e)
The maximum value is the same.(f) No. Answers will vary.
92. (a) (b)(c)
(d) Radius feet; Length feet93.
The model is a good fit.94.
The model is a good fit.95. Region 1: 259,370 Region 2: 223,47096. Answers will vary.
Answers will vary.97. (a)
(b)(c) Vertex:(d) The results are approximately equal.
98.99. False. A fifth-degree polynomial can have at most four
turning points.100. True. has one repeated solution.101. True. The degree of the function is odd and its leading
coefficient is negative, so the graph rises to the left andfalls to the right.
102. (a) Degree: 3; Leading coefficient: positive(b) Degree: 2; Leading coefficient: positive(c) Degree: 4; Leading coefficient: positive(d) Degree: 5; Leading coefficient: positive
103.
−3 −2 −1 1 2 3−1
1
2
3
4
5
x
y
f �x� � �x � 1�6
x � 200
�15.22, 2.54�t � 15
−10 45
−5
60
7120
13
180
7140
13
200
� 7.72� 1.93
00
2
150
r ≥ 0V �163 �r 3
00
6
4000
��
V � 3456;x � 3,
0 inches < x < 6V � �384x2 � 2304xA � �2x2 � 12x
x � 2.51 2 3 4 5 6
120
240
360
480
600
720
x
V
0 < x < 6
x � 6
0 180
3600
��
0 < x < 18 � x�36 � 2x�2
� �36 � 2x��36 � 2x�x V � l � w � h
��4, �3, ��1, 0, �0, 1, �3, 4; � ±3.113, ±0.556
��2, �1, �0, 1; � �1.585, 0.779
�0, 1, �6, 7, �11, 12; � 0.845, 6.385, 11.588
��1, 0, �1, 2, �2, 3; � �0.879, 1.347, 2.532
x 1 2 3 4 5 6 7
V 1156 2048 2700 3136 3380 3456 3388
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d.Precalculus with Limits, Answers to Section 2.2 11
(Continued)
(a) Vertical shift of two units; Even(b) Horizontal shift of two units; Neither even nor odd(c) Reflection in the y-axis; Even(d) Reflection in the x-axis; Even(e) Horizontal stretch; Even(f) Vertical shrink; Even(g) Neither odd nor even(h) Even
104. (a)
is decreasing. is increasing.(b) Either always increasing or always decreasing. The
behavior is determined by a.(c)
Because is not always increasing or alwaysdecreasing, cannot be written in the form
105. 106.107. 108.
109. 110. 111.
112. 113. 114.
115. 116.
117. Horizontal translation four units to the left of
118. Reflection in the x-axis and vertical shift of three units upof
119. Horizontal translation one unit left and vertical translationfive units down of
120. Reflection in the x-axis, horizontal translation, and verti-cal translation of
121. Vertical stretch by a factor of 2 and vertical translationnine units up of
122. Vertical shrink, reflection in the x-axis, horizontal shift of 3 units to the left, and vertical shift of 10 units up of
y
x1−1 2
1
2
3
4
5
6
7
8
9
3 4 5 6 7 8 9
y � x�
y
x−6
−2
1
2
3
4
5
6
−3 −2 −1 21
y � x�
y
x3
−3
3
6
9
12
15
−3 6 9 12 15
y � �x
y
x−3 −2 −1
−5
−3
−2
−1
1
1 2 3
y � �x
y
x−4 −3 −1
−4
−3
−2
−1
1
2
4
1 3 4
y � x2
y
x−7 −6 −5 −4 −3 −2 −1
−1
1
2
3
4
5
6
7
1
y � x2
�2 ± �313
�5 ± �1854
4 ± �141 ± �22�12
�54, 13�
23, 8�
72, 4
�y � 6��y2 � 6y � 36�x2�4x � 5��x � 3�x�6x � 1��x � 10��5x � 8��x � 3�
H�x� � a�x � h�5 � k.H
H�x�
−9 9
−6
6
y2y1
−12 12
−8
y1y2
8
g�x� � x16;g�x� � x3;
333202CB02_AN.qxd 1/1/70 09:36 AM Page 11
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d.
Precalculus with Limits, Answers to Section 2.3 12
Section 2.3 (page 159)
Vocabulary Check (page 159)1. dividend; divisor; quotient; remainder2. improper; proper 3. synthetic division4. factor 5. remainder
1. Answers will vary. 2. Answers will vary.
3. 4.
5. 6. 7.
8. 9.
10. 11.
12. 13.
14. 15.
16. 17.
18. 19.
20. 21. 22.
23. 24.
25.
26.
27.
28.
29. 30.
31.
32.
33.
34. 35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45. (a) 1 (b) 4 (c) 4 (d) 195446. (a) 14 (b) 3122 (c) 434 (d) 247. (a) 97 (b) (c) 17 (d)48. (a) (b) 20 (c) 65.5 (d) 566849. Zeros:50. Zeros:51. Zeros:
52. Zeros:
53. Zeros:
54. Zeros:
55.Zeros:
56.Zeros:
57. (a) Answers will vary. (b)(c) (d)(e)
58. (a) Answers will vary. (b)(c) (d)(e)
59. (a) Answers will vary. (b)(c)(d)(e)
60. (a) Answers will vary.
(b)(c) f �x� � �4x � 3��2x � 1��x � 2��x � 4�
�4x � 3�, �2x � 1�
−180
−6 6
20
1, 2, 5, �4f �x� � �x � 1��x � 2��x � 5��x � 4�
�x � 1�, �x � 2�
−4 3
−10
35
13, �3, 2f �x� � �3x � 1��x � 3��x � 2�
3x � 1−1
−6 6
7
12, �2, 1f �x� � �2x � 1��x � 2��x � 1�
2x � 12 � �5, 2 ��5, �3
�x � 2 � �5 ��x � 2 � �5 ��x � 3�;1, 1 ��3, 1 � �3
�x � 1��x � 1 � �3 ��x � 1 � �3 �;�2, ��2, �2�x � �2 ��x � �2 ��x � 2�;��3, �3, �2�x � �3 �� x � �3 ��x � 2�;
23, 34, 14�3x � 2��4x � 3��4x � 1�;
12, 5, 2�2x � 1��x � 5��x � 2�;
�4, �2, 6�x � 4��x � 2��x � 6�;2, �3, 1�x � 2��x � 3��x � 1�;
�2.5�199�
53
f �2 � �2 � � 0f �x� � �x � 2 ��2 ���3x2 � �2 � 3�2 �x � 8 � 4�2,f �1 � �3� � 0
f �x� � �x � 1 ��3���4x2 � �2 � 4�3�x � �2 � 2�3�,f ���5 � � 6
f �x� � �x � �5 ��x2 � �2 � �5 �x � 2�5 � 6,
f ��2 � � �8
f �x� � �x � �2 ��x2 � �3 � �2 �x � 3�2 � 8,
f �15� �
135f �x� � �x �
15��10x2 � 20x � 7� �
135 ,
f ��23� �
343f �x� � �x �
23��15x3 � 6x � 4� �
343 ,
f �x� � �x � 2��x2 � 7x � 3� � 2, f ��2� � 2
f (x) � �x � 4��x2 � 3x � 2� � 3, f �4� � 3
3x 2 �1
2x �
3
4�
49
8x � 12
4x2 � 14x � 30�x 2 � 3x � 6 �11
x � 1
�x3 � 6x2 � 36x � 36 �216
x � 6
�3x3 � 6x 2 � 12x � 24 �48
x � 2
�3x3 � 6x2 � 12x � 24 �48
x � 2
x2 � 9x � 81x2 � 8x � 64
x4 � 16x3 � 48x 2 � 144x � 312 �856
x � 3
10x3 � 10x2 � 60x � 360 �1360
x � 6
5x2 � 10x � 26 �44
x � 2
5x2 � 14x � 56 �232
x � 4
3x2 � 2x � 12�x2 � 10x � 25
9x 2 � 164x2 � 95x 2 � 3x � 2
3x2 � 2x � 52x �17x � 5
x2 � 2x � 1
x � 3 �6x2 � 8x � 3
�x � 1�3x2 �
x2 � 7
x3 � 1
x2 � 2x � 4 �2x � 11
x2 � 2x � 3x �
x � 9
x2 � 1
3x � 5 �2x � 3
2x2 � 14 �
9
2x � 1
7 �11
x � 2x2 � 7x � 18 �
42x � 3
x3 � 3x2 � 12x2 � 4x � 3
x2 � 3x � 15x � 32x � 4
−12 12
−8
8
−9 9
−6
6
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d.Precalculus with Limits, Answers to Section 2.3 13
(Continued)
(d)
(e)
61. (a) Answers will vary. (b)(c)(d)(e)
62. (a) Answers will vary. (b)(c) (d)(e)
63. (a) Answers will vary. (b)(c) (d)(e)
64. (a) Answers will vary. (b)(c)(d)(e)
65. (a) Zeros are 2 and (b) (c)
66. (a) Zeros are 4 and (b) (c)
67. (a) Zeros are and (b)(c)
68. (a) Zeros are and (b)(c)
69. 70.
71. 72.73. (a) and (b)
(c)
Answers will vary.(d) 1614 thousand. No, because the model will approach
negative infinity quickly.74. (a) and (b)
(c) $49.3875. False. is a zero of f.76. True.
77. True. The degree of the numerator is greater than thedegree of the denominator.
78. (a)(b)
79. 80.81. The remainder is 0.82. Multiply the divisor and the quotient and add the remain-
der to obtain the dividend.83. 84.85. 0; is a factor of f.86. Because is in factored form, it is easier to evaluate
directly.
87. 88. 89. 90.
91. 92.
93.94.95.96. f �x� � x4 � 3x3 � 5x2 � 9x � 2
f �x� � x3 � x2 � 7x � 3f �x� � x2 � 5x � 6f �x� � x3 � 7x2 � 12x
�3 ± �212
�3 ± �32
54
, 32
�75
, 2±�21
4±
53
f �x�x � 3
c � 42c � �210
x2n � xn � 3x2n � 6xn � 9f �x� � ��x � 3�x2 � 1 � �x3 � 3x2 � 1f �x� � �x � 2�x2 � 5 � x3 � 2x2 � 5
f �x� � �2x � 1��x � 1��x � 2��x � 3��3x � 2��x � 4�
�47
R � 0.00260x3 � 0.0292x 2 � 1.558x � 15.63
20
12
40
M � �0.242x3 � 12.43x 2 � 173.4x � 2118
31200
13
1800
x 2 � 9x � 1, x � ±2x2 � 3x, x � �2, �1
x 2 � 7x � 8, x � �82x2 � x � 1, x �32
f �s� � �s � 6��s � �3 ��5 ��s � �3 ��5 �x � 6
�5.236.6, �0.764,h �t� � �t � 2��t � �2 � �3 � �t � �2 � �3 �x � �2
�3.732.�2, �0.268,g�x� � �x � 4��x � �2 ��x � �2 �x � 4�±1.414.
f �x� � �x � 2��x � �5 ��x � �5 �x � 2�±2.236.
−8 8
−240
60
±4�3, �3f �x� � �x � 4�3 ��x � 4�3 ��x � 3�
x � 4�3−6
−6 6
14
±�5, 12f �x� � �x � �5 ��x � �5 ��2x � 1��x � �5 �
−4 4
−80
100
3, �52, 35f �x� � �x � 3��2x � 5��5x � 3�
x � 3−40
−9 3
320
�7, �12, 23
f �x� � �x � 7��2x � 1��3x � 2�x � 7
−3 5
−380
40
�34, 12, �2, 4
t 3 4 5 6 7 8
1703 1608 1531 1473 1430 1402M(t)
t 9 10 11 12 13
1388 1385 1392 1409 1433M(t)
333202CB02_AN.qxd 1/1/70 09:36 AM Page 13
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d.
Precalculus with Limits, Answers to Section 2.4 14
Section 2.4 (page 167)
Vocabulary Check (page 167)1. (a) iii (b) i (c) ii 2.3. complex numbers; 4. principal square5. complex conjugates
1. 2.
3. 4. 5.
6. 7. 8.
9. 10. 11. 8
12. 45 13. 14.
15. 16. 17.
18. 19. 4 20.
21. 22. 4 23.
24. 25. 26.
27. 28. 29.
30. 31. 24 32. 18
33. 34. 35.
36. 37. 38.
39. 40.
41. 20 42.
43. 44.
45. 46. 47.
48. 49. 50.
51. 52. 53.
54. 55. 56.
57. 58. 59.
60. 61. 62.
63.
64.
65. 66. 67.
68. 69. 70.
71. 72. 73.
74. 75. 76.
77. 78. 79.
80. 81. 82.
83. (a)
(b)
84. (a) 8 (b) 8 (c) 8
85. (a) 16 (b) 16 (c) 16 (d) 16
86. (a) 1 (b) i (c) (d)
87. False. If the complex number is real, the number equals its conjugate.
88. True.
89. False.
90.
91–92. Proof
93.
94.
95.
96.
97. 98. 14
99. 100.
101.
102.
103. 1 liter
r ���m1m2F
F
a ��3V�b
2�b
�43
272
�31
4x2 � 20x � 25
3x2 �232 x � 2
x3 � x2 � 2x � 6
�x2 � 3x � 12
��6��6 � �6 i�6 i � 6i2 � �6
i44 � i150 � i74 � i109 � i61 � 1 � 1 � 1 � i � i � 1
56 � 56
36 � 6 � 14 �?
56
��i�6 �4� ��i�6 �2
� 14 �?
56
x 4 � x2 � 14 � 56
�i�1
z �11,240
877�
4630877
i
z1 � 9 � 16i, z 2 � 20 � 10i
18
ii�8
�375�3i�i�5i
�4 � 2i�1 � 6i13
±�23
3i
57
±5�15
737
±�3414
i2 ± �2i
18
±�11
8i�
52
, �32
1
3± 2i
�2 ± 12i�3 ± i1 ± i
�2 � 4�6 i
�21 � 5�2� � �7�5 � 3�10�i�75�10�5�2
�2�3517 �
2017i62
949 �297949i
125 �
95i�
12 �
52i60
169 �25169i
�120
1681 �27
1681i8 � 4i�5 � 6i
4 � i45 �
35i5
2 �52i
841 �
1041i7i�5i
1 � �8, 9 � 4�2�8, 8
��15 i, 15�2�5i,
�3 � �2 i, 11�1 � �5 i, 6
7 � 12i, 1936 � 3i, 45�8i
�10�5 � 12i�9 � 40i
32 � 72i
12 � 30i6 � 22i5 � i
�4.2 � 7.5i16 �
76i17 � 18i
�14 � 20i3 � 3�2 i
�3 � 11i8 � 4i
11 � i0.02i0.3i
4 � 2i�1 � 6i
2i5�3 i
1 � 2�2 i2 � 3�3 i3 � 4i
4 � 3ia � 0, b � �52a � 6, b � 5
a � 13, b � 4a � �10, b � 6
a � bi
��1; �1
333202CB02_AN.qxd 1/1/70 09:37 AM Page 14
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d.Precalculus with Limits, Answers to Section 2.5 15
Section 2.5 (page 179)
Vocabulary Check (page 179)1. Fundamental Theorem of Algebra2. Linear Factorization Theorem 3. Rational Zero4. conjugate 5. irreducible over the reals6. Descartes’ Rule of Signs 7. lower; upper
1. 2. 0, 3. 4. 8
5. 6. 2, 7.
8.
9.
10. 11. 1, 2, 3 12.
13. 14. 1, 2, 6 15.
16. 3 17. 18. 19.
20. 21. 22.
23. 24.
25. (a)(b)
(c)
26. (a)
(b) (c)
27. (a)(b) (c)
28. (a)
(b) (c)
29. (a)(b) (c)
30. (a)(b) (c)
31. (a)
(b) (c)
32. (a)
(b) (c)
33. (a)
(b)
34. (a)
(b)
35. (a)
(b)
36. (a)
(b)
37. 38.
39. 40.
41.
42. x 4 � 8x 3 � 9x2 � 10x � 100
3x4 � 17x3 � 25x2 � 23x � 22
x3 � 10x 2 � 33x � 34x3 � 4x 2 � 31x � 174
x3 � 4x 2 � 9x � 36x3 � x2 � 25x � 25
g�x� � �x � 3��x � 3��2x � 3��3x � 1�±3, 1.5, 0.333
h�x� � x�x � 3��x � 4��x � �2 ��x � �2 �0, 3, 4, �±1.414
P�t) � �t � 2��t � 2��t � �3 ��t � �3 �±2, �±1.732
f �x� � �x � 1��x � 1��x � �2 ��x � �2 �±1, �±1.414
�2, 1
8±�145
8−8 8
−24
8
±14, ±3
4, ±94±1, ±2, ±3, ±6, ±9, ±18, ±1
2, ±32, ±9
2,
1, 34, �18
−1 3
−2
6
±1, ±3, ±12, ±3
2, ±14, ±3
4, ±18, ±3
8, ± 116, ± 3
16, ± 132, ± 3
32
±2, ±12
−8 8
−15
9
±1, ±2, ±4, ±12, ±1
4
�12, 1, 2, 4
−4 8
−8
16
±1, ±2, ±4, ±8, ±12
�1, 32, 52
−9 −6 −3 6 9 12
12
15
x
y
±1, ±3, ±5, ±15, ±12, ±3
2, ±52, ±15
2 , ±14, ±3
4, ±54, ±15
4
�14, 1, 3
−6 −4 −2 2 4 6 8 10
−6
−4
2
4
x
y
±1, ±3, ±12, ±3
2, ±14, ±3
4
23, 2, 4
−4 −2 6 8 10 12
−6
−4
2
4
6
8
10
x
y
±1, ±2, ±4, ±8, ±16, ±13, ±2
3, ±43, ±8
3, ±163
�2, �1, 2
−6 −4 4 6
−8
−6
−4
2
4
x
y
±1, ±2, ±4
�2, 0, 1�6, 12, 1
0, �1, �3, 4�1, 2±1, 5, 52
�2, 3, ±23
13, 31
2, �1
�1, �101, �1, 4
�2, �1, 3±1, ±2, ±12, ±1
4
±52, ±9
2, ±152 , ±45
2±1, ±3, ±5, ±9, ±15, ±45, ±12, ±3
2,
±1, ±2, ±4, ±8, ±16
±1, ±3±3i3,�6, ± i
�5,2, �4±1�3,0, 6
333202CB02_AN.qxd 1/1/70 09:37 AM Page 15
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d.
Precalculus with Limits, Answers to Section 2.5 16
(Continued)
43. (a) (b)
(c)
44. (a)
(b)
(c)
45. (a)
(b)
(c)
46. (a)
(b)
(c)
47. 48. 49.
50. 51. 52.
53. 54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73. 74.
75. 76.
77. 78.79. No real zeros 80. Two or no positive zeros81. No real zeros 82. Two or no positive zeros83. One positive zero 84. One or three positive zeros
85. One or three positive zeros
86. One or three negative zeros
87–90. Answers will vary.
91. 92. 93. 94.
95. 96. 97. 98.
99. d 100. a 101. b 102. c
103. (a)
(b)Domain:
(c)
(d) 8 is not in the domain of V.
104. (a) Answers will vary.(b)
(c) the value is
physically impossible because x is negative.
105. or $384,000
106. or $315,000
107. (a)
(b) 4 feet by 5 feet by 6 feet
108. (a) feet squared
(b) feet
feet
(c) the corral hasdimensions 313.2 feet by 191.6 feet.
109. or 4000 units
110. No. Setting and solving the resulting equationyields imaginary roots.
111. No. Setting and solving the resultingequation yields imaginary roots.
p � 9,000,000
h � 64
x � 40,
A � �160 � x��250 � 2x� � 60,000;
250 ��410 � �248,100
2� 294.05
160 ��410 � �248,100
2� 204.05
A � �160 � x��250 � x� � 60,000
V � x3 � 9x2 � 26x � 24 � 120
x � 31.5,
x � 38.4,
x �15 � 15�5
215,
15 ± 15�5
2;
20 inches � 20 inches � 40 inches
0 300
18,000
12, 72, 8;
1.82 centimeters � 5.36 centimeters � 11.36 centimeters
Length of sides ofsquares removed
V
x1 3 42 5
25
50
75
100
125
Vol
ume
of b
ox
0 < x < 92
V � x�9 � 2x��15 � 2x�
15
9
x
x
x9 − 2x 15 − 2x
�2, �13, 12±1, 14�3, 12, 4±2, ±3
2
23�
34�
32, 13, 321, �1
2
1 ± �3 i, 2�2, �12, ± i
13 ± 2
3i, 1�34, 1 ± 1
2i
1 ± 2i, 12�10, �7 ± 5i
�x � 2i��x � 2i��x � 5i��x � 5i�±2i, ±5i;
�x � i��x � i ��x � 3i��x � 3i�± i, ±3i;
�x � 3�2�x � i��x � i��3, ± i;
�x � 2�2�x � 2i��x � 2i�2, ±2i;
�3x � 2��x � 1 � �3 i��x � 1 � �3 i�1 ± �3i, �23;
�5x � 1��x � 1 � �5 i��x � 1 � �5 i��15, 1 ± �5 i;
�x � 5��x � 2 � �3i��x � 2 � �3 i��2 ± �3i, �5;
�x � 2��x � 1 � �2 i��x � 1 � �2 i��2, 1 ± �2 i;
�x � 4��x � 3 � 2i��x � 3 � 2i�3 ± 2i, �4;
�x � 2��x � 2 � i ��x � 2 � i �2, 2 ± i;
�x � 1��x � 1 � i��x � 1 � i�1 ± i, 1;
�z � 1 � i��z � 1 � i�1 ± i;
�y � 5��y � 5��y � 5i��y � 5i�±5, ±5i;
�x � 3��x � 3��x � 3i��x � 3i�±3, ±3i;
�x � 5 � �2 ��x � 5 � �2 ��5 ± �2;
�x � 2 � �3 ��x � 2 � �3 �2 ± �3;
�x �1 � �223i
2 ��x �1 � �223i
2 �1 ± �223 i
2;
�x � 5i ��x � 5i �±5i;
�2, �1 ± 3i2, �3 ± �2 i, 1
�23, 1 ± �3 i�3 ± i , 14�3, 5 ± 2i
±2i, 1, �12�1, ±3i�
32, ±5i
�x �3 � �29
2 ��x �3 � �29
2 ��x � 2i��x � 2i�
�x 2 � 4��x �3 � �29
2 ��x �3 � �29
2 ��x 2 � 4��x 2 � 3x � 5�
�x � 1 � �2 i��x � 1 � �3 ��x � 1 � �3 ��x � 1 � �2 i��x � 1 � �3 ��x � 1 � �3 ��x2 � 2x � 3��x2 � 2x � 2��x2 � 2x � 3�
�x � 1 � �2 i��x � �6��x � �6��x � 1 � �2 i��x � �6 ��x � �6 ��x 2 � 2x � 3��x 2 � 6��x 2 � 2x � 3��x � 3i ��x � 3i ��x � �3 ��x � �3 �
�x2 � 9��x � �3 ��x � �3 ��x2 � 9��x2 � 3�
333202CB02_AN.qxd 1/1/70 09:37 AM Page 16
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d.Precalculus with Limits, Answers to Section 2.5 17
(Continued)
112. (a)
(b) (c) 2000(d) 2001(e) Yes, the attendance
will continue to grow.
113. False. The most complex zeros it can have is two, and theLinear Factorization Theorem guarantees that there arethree linear factors, so one zero must be real.
114. False. f does not have real coefficients.
115. 116.
117. 118.
119. The zeros cannot be determined.
120.
121. (a) (b) (c) (d)
122. (a) No (b) No123. Answers will vary. There are infinitely many possible
functions for f. Sample equation and graph:
124. Answers will vary. Sample graph:
125. Answers will vary.
126. (a)
(b) The graph touches the axis at
(c) The least possible degree of the function is 4, becausethere are at least four real zeros (1 is repeated) and afunction can have at most the number of real zerosequal to the degree of the function. The degree cannotbe odd by the definition of multiplicity.
(d) Positive. From the information in the table, it can be concluded that the graph will eventually rise to theleft and rise to the right.
(e)
(f)
127. (a) (b)
128. (a) Not correct because f has as an intercept.
(b) Not correct because the function must be at least afourth-degree polynomial.
(c) Correct function
(d) Not correct because has as an intercept.
129. 130.
131. 132. 106
133. 134.
135. 136.
137. 138.
x42 6 8
6
4
8
10
−2(−4, 0)
(4, 2)(0, 2)
(8, 4)
yy
xx−1−2 1 2
4
3
(−1, 0)
(0, 2)(1, 2)
(2, 4)
y
x1−1−2−3−4
1
2
3
4
−1
−2
(2, 0)
(0, 2)
(−2, 2)
(−4, 4)
y
x42 6 8
6
8
10
−2(−2, 0)
(2, 4)
(0, 4)
(4, 8)
y
x2 31−1−2 4
2
3
−2
−3
(2, 0)(0, 0)
(4, 2)
y
(−2, −2)
x2 3 4 5 6
1
−1
−2
2
3
4
(0, 0)
(4, 2)
(2, 2)
(6, 4)
y
20 � 40i
12 � 11i�11 � 9i
��1, 0�k
�0, 0�
x2 � 2ax � a2 � b2x2 � b
x−1−3 2
(−2, 0)(1, 0) (4, 0)
−4−6−8
2
3 5
−10
y
f �x� � x4 � 4x3 � 3x2 � 14x � 8
x � 1.x-
�2, 1, 4
x4 5
50
10
(−1, 0)
(3, 0)
(1, 0) (4, 0)
y
x−4
8
4
4 8 12−8
(−2, 0)
12
, 0 ( ((3, 0)
y
f �x� � �2x3 � 3x2 � 11x � 6
k > 4k < 0k � 40 < k < 4
�r1, �r2, �r3
r1
2,
r2
2,
r3
25 � r1, 5 � r2, 5 � r3
r1, r2, r3r1, r2, r3
70
13
12
A � 0.0167x3 � 0.508x2 � 5.60x � 13.4
333202CB02_AN.qxd 1/1/70 09:37 AM Page 17
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d.
Precalculus with Limits, Answers to Section 2.6 18
Section 2.6 (page 193)
Vocabulary Check (page 193)1. rational functions 2. vertical asymptote3. horizontal asymptote 4. slant asymptote
1. (a)
(b) Vertical asymptote:Horizontal asymptote:
(c) Domain: all real numbers x except
2. (a)
(b) Vertical asymptote:Horizontal asymptote:
(c) Domain: all real numbers x except
3. (a)
(b) Vertical asymptotes:Horizontal asymptote:
(c) Domain: all real numbers x except
4. (a)
(b) Vertical asymptotes:Horizontal asymptote:
(c) Domain: all real numbers x except 5. Domain: all real numbers x except
Vertical asymptote:Horizontal asymptote:
6. Domain: all real numbers x except Vertical asymptote:Horizontal asymptote:
7. Domain: all real numbers x except Vertical asymptote:Horizontal asymptote:
8. Domain: all real numbers x except Vertical asymptote:Horizontal asymptote:
9. Domain: all real numbers x except Vertical asymptotes:
10. Domain: all real numbers x except Vertical asymptote:Horizontal asymptote: none
11. Domain: all real numbers xHorizontal asymptote:
12. Domain: all real numbers xHorizontal asymptote:No vertical asymptote
13. d 14. a 15. c 16. b17. 1 18. None 19. 6 20. 221. Domain: all real numbers x except
Vertical asymptote: horizontal asymptote:22. Domain: all real numbers except
Vertical asymptote: horizontal asymptote:23. Domain: all real numbers x except 3;
Vertical asymptote: horizontal asymptote:24. Domain: all real numbers x except 2;
Vertical asymptote: horizontal asymptote:25. Domain: all real numbers x except
Vertical asymptote: horizontal asymptote:26. Domain: all real numbers x except
Vertical asymptote: horizontal asymptote:27. (a) Domain: all real numbers x except
(b) y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
−3 −1
−2
−1
1
2
x
( (0, 12
y
y � 0x � �2
�0, 12�x � �2
y � 1x � �13;
32;x � �
13,
y �12x �
12;
x � �1, 12;y � 1x � 1;
x � 1,y � 1x � 3;
x � �1,y � 0x � 3;
x � ±3;xy � 0x � �4;
x � ±4;
y � 3
y � 3
x � �1x � �1
x � ±1x � ±1
y � �52
x � �12
x � �12
y � �1x � 2
x � 2y � 0
x � 2x � 2
y � 0x � 0
x � 0x � ±1
y � 0x � ±1
x � ±1y � 3
x � ±1
x � 1y � 5
x � 1
x � 1y � 0
x � 1
x
0.5
0.9
0.99
0.999 �1000
�100
�10
�2
f �x� x
1.5 2
1.1 10
1.01 100
1.001 1000
f �x� x
5 0.25
10
100
1000 0.001
0.01
0.1
f �x�
0.5
0.9
0.99
0.999 �4995
�495
�45
�5
f �x�x
1.5 15
1.1 55
1.01 505
1.001 5005
f �x�x
5 6.25
10
100
1000 5.005
5.05
5.55
f �x�x
x
0.5
0.9
0.99
0.999 �1498
�147.8
�12.79
�1
f �x� x
5 3.125
10
100
1000 3
3.0003
3.03
f �x�x
1.5 5.4
1.1 17.29
1.01 152.3
1.001 1502
f �x�
0.5
0.9
0.99
0.999 �1999
�199
�18.95
�2.66
f �x�x
1.5 4.8
1.1 20.95
1.01 201
1.001 2001
f �x�x
5
10
100 0.04
1000 0.004
0.40
0.833
f �x�x
333202CB02_AN.qxd 1/1/70 09:37 AM Page 18
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d.Precalculus with Limits, Answers to Section 2.6 19
(Continued)
28. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
29. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
30. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
31. (a) Domain: all real numbers x except (b) x-intercept:
y-intercept:(c) Vertical asymptote:
Horizontal asymptote:
(d)
32. (a) Domain: all real numbers x except (b) x-intercept:
y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
33. (a) Domain: all real numbers x(b) Intercept:(c) Horizontal asymptote:(d)
34. (a) Domain: all real numbers t except (b) t-intercept: (c) Vertical asymptote:
Horizontal asymptote:(d)
−2 −1 1 2
−3
−1
t
( ), 012
y
y � �2
t � 0�12, 0�
t � 0
−2 −1 1 2
−1
2
3
x(0, 0)
y
y � 1�0, 0�
−2 −1 2 3 4
4
5
6
x
(0, 1) , 013( )
y
y � 3x � 1
�0, 1��1
3, 0�x � 1
( (
−6 −4 2 4x
6
52
− , 0
(0, 5)
y
y � 2x � �1
�0, 5���5
2, 0�x � �1
1 2 4
−3
−2
−1
1
2
3
x
( (0, 13
y
y � 0x � 3
�0, 13�x � 3
−4 −3 −1
−2
−1
1
2
x( (0, − 1
2
y
y � 0x � �2
�0, �12�
x � �2
2 4 5 6
−3
−2
−1
1
2
3
x
( (0, 13−
y
y � 0x � 3
�0, �13�
x � 3
333202CB02_AN.qxd 1/1/70 09:37 AM Page 19
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d.
Precalculus with Limits, Answers to Section 2.6 20
(Continued)
35. (a) Domain: all real numbers s
(b) Intercept:
(c) Horizontal asymptote:
(d)
36. (a) Domain: all real numbers x except
(b) y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
37. (a) Domain: all real numbers x except
(b) x-intercepts: and
y-intercept:
(c) Vertical asymptotes:
Horizontal asymptote:
(d)
38. (a) Domain: all real numbers x except
(b) x-intercepts:
y-intercept:
(c) Vertical asymptotes:
Horizontal asymptote:
(d)
39. (a) Domain: all real numbers x except
(b) x-intercept:
y-intercept:
(c) Vertical asymptotes:
Horizontal asymptote:
(d)
40. (a) Domain: all real numbers x except 1, 3
(b) x-intercepts:
y-intercept:
(c) Vertical asymptotes:
Horizontal asymptote:
(d)
41. (a) Domain: all real numbers x except
(b) Intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d) y
x−2−4−6 4 6
−4
−6
2
4
6
(0, 0)
y � 1
x � 2
�0, 0�x � 2, �3
x
1
2
3
2 4 5
−2
−3
−4
−5
4
13
−0,( (
( 1, 0)−
(2, 0)
y
y � 0
x � 3x � 1,x � �2,
�0, �13�
��1, 0�, �2, 0�x � �2,
y
x
0, −32( (
, 012( (−
(3, 0)
−4 −3 43
3
6
9
y � 0
x � ±1x � 2,
�0, �32�
�3, 0�, ��12, 0�
x � ±1, 2
y
x−4−6 2 4 6
−2
−4
−6
2
4
6
(−2, 0)
(4, 0)
(0, 0.88)
y � 1
x � ±3
�0, 0.88�
��2, 0�, �4, 0�
x � ±3
y
x−4−6 6
2
4
6
(1, 0)
(4, 0)
y � 1
x � ±2
�0, �1�
�4, 0��1, 0�
x � ±2
1 3
−4
−3
−2
−1
x( (0, − 1
4
y
y � 0
x � 2
�0, �14�
x � 2
1 2
−2
−1
1
2
s(0, 0)
y
y � 0
�0, 0�
333202CB02_AN.qxd 1/1/70 09:37 AM Page 20
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d.Precalculus with Limits, Answers to Section 2.6 21
(Continued)
42. (a) Domain: all real numbers x except
(b) y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
43. (a) Domain: all real numbers x except
(b) x-intercept:
y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
44. (a) Domain: all real numbers x except 2
(b) x-intercept:
y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
45. (a) Domain: all real numbers t except
(b) t-intercept:
y-intercept:
(c) Vertical asymptote: None
Horizontal asymptote: None
(d)
46. (a) Domain: all real numbers x except (b) x-intercept:
y-intercept:(c) Vertical asymptote: None
Horizontal asymptote: None(d)
47. (a) Domain of f : all real numbers x except Domain of g: all real numbers x
(b) Vertical asymptotes: none(c)
(d)
(e) Because there are only a finite number of pixels, thegraphing utility may not attempt to evaluate the function where it does not exist.
48. (a) Domain of f : all real numbers x except Domain of g: all real numbers x
(b) x; Vertical asymptotes: none(c)
x � 0, 2
−4
−3
2
1
x � 1;
x � �1
y
x
(0, 4)
(−4, 0)
−2−6 2 4 6−2
2
4
6
8
10
�0, 4���4, 0�
x � 4
y
t−1−2−3 1 2 3
−1
−2
−3
1
2
3
(1, 0)
(0, −1)
�0, �1��1, 0�
t � �1
y
x−1−2−3−4 3 4
1
(0, −2)
, 023( (
y �32
x � �0.5
�0, �2��2
3, 0�x � �0.5,
y
x−2−3−4−5 2 3
2
3
4
, 0 12 ))
0, − 13 ))
1
y � 1
x � �32
�0, 13��1
2, 0�x � �
32, 2
y
x
(0, −1.66)2 4 6 8
−4
−6
2
4
6
y � 0
x � 3
�0, �1.66�
�4x � 3,
0 1
Undef. 0
0�1�1.5�2�2.5�3�4g�x�
�1�1.5�2.5�3�4f �x�
�0.5�1�1.5�2�3x
0 1 1.5 2 2.5 3
Undef. 1 1.5 Undef. 2.5 3
0 1 1.5 2 2.5 3�1g�x�
�1f �x�
�1x
333202CB02_AN.qxd 1/1/70 09:37 AM Page 21
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d.
Precalculus with Limits, Answers to Section 2.6 22
(Continued)
(d)
(e) Because there are only a finite number of pixels, thegraphing utility may not attempt to evaluate the function where it does not exist.
49. (a) Domain of f: all real numbers x except Domain of g: all real numbers x except
(b) Vertical asymptote:
(c)
(d)
(e) Because there are only a finite number of pixels, thegraphing utility may not attempt to evaluate thefunction where it does not exist.
50. (a) Domain of f : all real numbers x except Domain of g: all real numbers x except
(b) Vertical asymptote:
(c)
(d)
(e) Because there are only a finite number of pixels, thegraphing utility may not attempt to evaluate the function where it does not exist.
51. (a) Domain: all real numbers x except (b) x-intercepts:(c) Vertical asymptote:
Slant asymptote:
(d)
52. (a) Domain: all real numbers x except (b) No intercepts(c) Vertical asymptote:
Slant asymptote:(d)
53. (a) Domain: all real numbers x except (b) No intercepts(c) Vertical asymptote:
Slant asymptote:(d)
54. (a) Domain: all real numbers x except (b) x-intercepts:(c) Vertical asymptote:
Slant asymptote:(d)
55. (a) Domain: all real numbers x except (b) No intercepts(c) Vertical asymptote:
Slant asymptote: y � xx � 0
x � 0
−8 −6 −4 −2 4 6 8
−8
−6
−4
2
4
6
8
x
y = −x
(−1, 0) (1, 0)
y
y � �xx � 0
��1, 0�, �1, 0�x � 0
y = 2x
−6 −4 −2 2 4 6
−6
2
4
6
x
y
y � 2xx � 0
x � 0
y
x−4 −2−6 2 4 6
−2
−4
2
4
6
y = x
y � xx � 0
x � 0
y
x−4−6 6
−2
−4
−6
2(−2, 0)
(2, 0)
y = x
y � xx � 0
�2, 0�, ��2, 0�x � 0
−1
−3
8
3
x � 42
x � 4;
x � 4x � 3, 4
−3
−2
3
2
x � 01x;
x � 0x � 0, 2
−2
−2
4
2
0 0.5 1 1.5 2 3
Undef. 2 1 Undef.
Undef. 2 1 13
12
23�2g�x�
13
23�2f �x�
�0.5x
x 0 1 2 3 4 5 6
Undef. Undef. 2 1
Undef. 2 1�2�1�23�
12g�x�
�1�23�
12f �x�
333202CB02_AN.qxd 1/1/70 09:37 AM Page 22
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d.Precalculus with Limits, Answers to Section 2.6 23
(Continued)
(d)
56. (a) Domain: all real numbers x except (b) Intercept:(c) Vertical asymptote:
Slant asymptote:(d)
57. (a) Domain: all real numbers t except (b) intercept:(c) Vertical asymptote:
Slant asymptote:(d)
58. (a) Domain: all real numbers x except (b) Intercept:(c) Vertical asymptote:
Slant asymptote:(d)
59. (a) Domain: all real numbers x except (b) Intercept:(c) Vertical asymptotes:
Slant asymptote:(d)
60. (a) Domain: all real numbers x except (b) Intercept:(c) Vertical asymptotes:
Slant asymptote:(d)
61. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Slant asymptote:(d)
62. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Slant asymptote:(d)
−9 −6 −3 3 6 9 12 15
−9
3
6
9
12
15
x
( (0, − 52
y = 2x − 1
y
y � 2x � 1x � 2
�0, �52�
x � 2
−4 −2 2 4 6 8
−4
2
4
6
8
x(0, −1)
y = x
y
y � xx � 1
�0, �1�x � 1
−8 −6 −4 4 6 8
4
6
8
x
y = x
(0, 0)
12
y
y �12x
x � ±2�0, 0�
x � ±2
−6 −4 −2 2 4 6x
2(0, 0)
y = x
y
y � xx � ±1
�0, 0�x � ±1
y
x
13
123
23
43
13
1−1
y = x − 13
19 (0, 0)
y �13x �
19
x � �13
�0, 0�x � �
13
y
t
y = 5 − t
(0, −0.2)
−10−15−20 10
5
15
20
25
−5
y � �t � 5t � �5
�0, �0.2�y-t � �5
−4 2 4 6 8
−4
−2
2
4
6
8
x(0, 0)
y = x + 1
y
y � x � 1x � 1
�0, 0�x � 1
−6 −4 −2 2 4 6
−6
2
4
6
x
y = x
y
333202CB02_AN.qxd 1/1/70 09:37 AM Page 23
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d.
Precalculus with Limits, Answers to Section 2.6 24
(Continued)
63. (a) Domain: all real numbers x except
(b) y-intercept:
x-intercepts:
(c) Vertical asymptote:
Slant asymptote:
(d)
64. (a) Domain: all real numbers x except 2
(b) y-intercept:
x-intercepts:
(c) Vertical asymptote:
Slant asymptote:
(d)
65.
Domain: all real numbers x except
Vertical asymptote:
Slant asymptote:
66.
Domain: all real numbers x except
Vertical asymptote:
Slant asymptote:
67.
Domain: all real numbers x except Vertical asymptote:Slant asymptote:
68.
Domain: all real numbers x except
Vertical asymptote:
Slant asymptotes:
69. (a) (b)
70. (a) (b) 0
71. (a) (b)
72. (a) (b) 1, 2
73. (a)
(b) $28.33 million; $170 million; $765 million(c) No. The function is undefined at
74. (a)
(b) $4411.76; $25,000; $225,000(c) No. The function is undefined at
75. (a) 333 deer, 500 deer, 800 deer (b) 1500 deer
76. (a) Answers will vary. (b)(c)
(d) Increases more slowly; 75%
200 400 600 800 1000
0.2
0.4
0.6
0.8
1.0
x
C
�0, 950
p � 100.
00
100
300,000
p � 100.
00
100
2,000
�1, 0�, �2, 0�±1�1, 0�, ��1, 0�
�0, 0��1��1, 0�
y � �12 x � 1
y � �12 x � 1
x � �4
x � �4
−16
−6
8
10
y � �x � 3y � �x � 3
x � 0x � 0
−12
−4
12
12
y � 2x � 1
y � 2x � 1
x � �1
x � �1
−12
−10
12
6
y � x � 2
y � x � 2
x � �3
x � �3
−14
−8
10
8
y
x2−2
12
18
24
30
−6 4 6
(−2, 0)
(0, −2)
y = 2x + 7
, 0− 12( (
y � 2x � 7
x � 1
��2, 0�, ��12, 0�
�0, �2�x � 1,
y
x−1−3−4−5−6 3
−12
−18
−24
−30
−36
6
12
18
(0.5, 0)
(0, 0.5)(1, 0)
y = 2x − 7
y � 2x � 7
x � �2
�0.5, 0�, �1, 0��0, 0.5�
x � �1, �2
333202CB02_AN.qxd 1/1/70 09:37 AM Page 24
Precalculus with Limits, Answers to Section 2.6 25
(Continued)
77. (a) Answers will vary. (b)
(c)
78.
79. (a) Answers will vary.
(b) Vertical asymptote:
Horizontal asymptote:
(c)
(d)
(e) Yes. You would expect the average speed for the roundtrip to be the average of the average speeds for the twoparts of the trip.
(f) No. At 20 miles per hour you would use more time inone direction than is required for the round trip at anaverage speed of 50 miles per hour.
80. (a)
The model is a good fit for the data.
(b) $763.8 million in sales
(c) No, horizontal asymptote at
81. False. Polynomials do not have vertical asymptotes.
82. False. The graph of crosses which
is a horizontal asymptote.
83.
84.
85. 86.
87.
88.
89.
90.
91.
92.
93. Answers will vary.
−
−2−4−6−8
x
0
22713
42
x ≥ 72x ≤ �
132 ,
20−2−4
−3x
4 6
7
8
�3 < x < 7
0
x
1−1−2−3 2 3
x < 0
0
x
1 2 3 4 5 6
103
x ≥ 103
�x � 6��x � �2��x � �2�
�x � 5��x � 2i��x � 2i�
�3x � 4��x � 9��x � 7��x � 8�
f �x� �x3
�x � 2��x � 1�
f �x� �2x2
x2 � 1
y � 0,f �x� �x
x2 � 1
y � 1454.
80
13
600
025 65
200
y � 25
x � 25
12.8 inches � 8.5 inches
11.75 inches � 5.87 inches
40
40
200
�4, �
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30 35 40 45 50 55 60
150 87.5 66.7 56.3 50 45.8 42.9y
x
333202CB02_AN.qxd 1/1/70 09:37 AM Page 25
Section 2.7 (page 204)
Vocabulary Check (page 204)1. critical; test intervals 2. zeros; undefined values3.
1. (a) No (b) Yes (c) Yes (d) No
2. (a) Yes (b) No (c) Yes (d) Yes
3. (a) Yes (b) No (c) No (d) Yes
4. (a) No (b) Yes (c) Yes (d) No
5. 6. 7. 8.
9. 10.
11. 12.
13. 14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25. 26. All real numbers
27. 28.29. 30.31. 32.33. 34.
(a) (a)
(b) (b)35. 36.
(a) (a)
(b) (b)37. 38.
39. 40.
41. 42.
43. 44.
45. 46.
47. 48.
−1−2−3 0 1 2 3
x
−1−2−3 0 1 2 3
x
��3, 0� � �2, ���3, �2 � �0, 3�
−1−2−3−4 10
x
−2−4
−33
4 6 820
4x
��, �3� � �0, ���34, 3� � �6, �
−14
−5
−2
−10−15 0 5
6
10
x2
−1−2−3−4−5
−
0
3
x
��14, �2� � �6, ���5, �32� � ��1, �
−2 −1
−
0 21
12
x3 6 9
5
12 15 18
x
��, �12� � �1, ��5, 15�
−1−2 0 1 2 3
x
−2 −1 10 2 3 4 5
x
��2, 3��, �1� � �4, �10
14
−1
x−1−2 210
x
��, 0� � � 14, ���, �1� � �0, 1�
x � �2, 5 ≤ x < x ≤ 41 ≤ x ≤ 42 ≤ x <
� < x ≤ �4,�2 ≤ x ≤ 0,
−12 12
−24
48
−12 12
−8
8
x ≤ �2, x ≥ 60 ≤ x ≤ 2
2 � �2 ≤ x ≤ 2 � �2x ≤ �1, x ≥ 3
−10
−4
14
12
−5 7
−2
6
��, 3��2, ���, 0 � �2, ���2, 0 � �2, ��3, �(�, 0� � �0, 32�
1 2 30−3 −2 −1
x
210−1
x
−2
12
x �12
4
x
−2−4−6−8 20
132
−
��132 , �2 � �2, �
x
−4 −3 −2 −1 0 1 2 3 4 5
��3, 2 � �3, �
0 1 2 3 4
x
��, 2
0 1 2 43
x
−1
��1, 1� � �3, �
x
543210−1−2
32 2
39− 32 2
39+
��, 32
��39
2 � � 32
��39
2, �
20
x
−8 −6 −4 −2−10
−4 + 21−4 − 21
��, �4 � �21 � ��4 � �21, �0−2−4 2 4 6 8
x2 − 5 2 + 5
��, 2 ��5 � � �2 � �5, �10−1−2−3
x
��3, 1�
−1−2−3−4 0 1 2
x
��, �3� � �1, �
0−1−2−3 1 2
x
��3, 2�−2
−1
2 40 6
7
8
xx
210−1−2−3−4−5−6
��1, 7���, �5 � �1, �
31 2 54
x
−8 −4−6
−7
0 2
3
4
x
−2
��, 2 � �4, ���7, 3�
x
−8 −6 −4 −2 0 2 4 6 8−1−2−3 0 1 2 3
x
��6, 6���3, 3�2, �1, 1, 47
2, 50, 2592, �3
2
P � R � C
Precalculus with Limits, Answers to Section 2.7 26
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Precalculus with Limits, Answers to Section 2.7 27
(Continued)
49.
50.
51. 52.
(a) (a)
(b) (b)
53. 54.
(a) (a)
(b) (b)55. 56.57. 58.59. 60.61. 62.63. 64.65. 66.67. (a) seconds (b)68. (a) seconds
(b) 0 seconds seconds and
69. 13.8 meters 36.2 meters70. 45.97 feet 174.03 feet71.72. 90,000 units 100,000 units; 73. (a)
(b)
2011
(c)(d)
2016 to 2021(e)(f) Answers will vary.
74. (a)
(b) 3.83 inches
75. ohms
76. (a) 1995 (b) (c) 2006 (d)
77. True. The test intervals are and
78. True. The -values are greater than zero for all values of
79. 80.
81.
82.
83. (a) If and can be any real number. If and
(b) 0
84. (a)
(b)
(c) The real zeros of the polynomial
85. 86.
87. 88.
89. 90. 32b2 � b2x2 � x
2x�x � 3��x2 � 3x � 9��x � 3��x � 2��x � 2�
�x � 7��x � 1��2x � 5�2
ax
b
+ − +
− − +
− + +
x � a, x � b
c > 0, b < �2�ac or b > 2�ac.a > 0c ≤ 0, ba > 0
��, �2�10 � �2�10, ���, �2�30 � �2�30, �
��, ���, �4 � �4, �
x.y
�4, �.�1, 4�,��3, 1�,��, �3�,
t � 16.25t � 5.1
R1 ≥ 2
Depth of the beam
Max
imum
saf
e lo
add
L
4 6 8 10 12
5,000
10,000
15,000
20,000
25,000
37 ≤ t ≤ 41
t � 31
0 230
80
30.00 ≤ p ≤ 32.00≤ x ≤40,000 ≤ x ≤ 50,000; 50.00 ≤ p ≤ 55.00
≤ L ≤≤ L ≤
4 � 2�2 seconds < t ≤ 8 seconds≤ t < 4 � 2�2
t � 84 seconds < t < 6 secondst � 10�1.19, 1.30��2.26, 2.39���4.42, 0.42���0.13, 25.13���1.13, 1.13���3.51, 3.51���3, 0 � �3, ���5, 0 � �7, ���4, 4��, 3 � �4, ���, �2 � �2, ���2, 2
� < x ≤ 0� < x <
1 ≤ x ≤ 4�x� ≥ 2
−6 6
−4
4
−6 6
−2
6
�2 ≤ x < �12 < x ≤ 4
�1 < x ≤ 20 ≤ x < 2
−15 15
−6
14
−6 12
8
−4
0 2 64
x
−2−4
1
��, �4� � ��2, 1� � �6, �
x
−1
−
43210
23
��, �1� � ��23, 1� � �3, �
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t 24 26 28 30 32 34
C 70.5 71.6 72.9 74.6 76.8 79.6
t 36 37 38 39
C 83.2 85.4 87.8 90.5
t 40 41 42 43
C 93.5 96.8 100.4 104.4
d 4 6 8 10 12
Load 2223.9 5593.9 10,312 16,378 23,792
333202CB02_AN.qxd 1/1/70 09:37 AM Page 27
Review Exercises (page 208)
1. (a) (b)
Vertical stretch Vertical stretch and reflection in the x-axis
(c) (d)
Vertical shift Horizontal shift
2. (a) (b)
Vertical shift Reflection in the x-axis andvertical shift
(c) (d)
Horizontal shift Vertical shrink and verticalshift
3. 4.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:x-intercepts: x-intercepts:
5. 6.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:
x-intercepts: x-intercepts:
7. 8.
Vertex: Vertex:Axis of symmetry: Axis of symmetry:
t-intercepts:x-intercepts: �2, 0�, �6, 0��1 ±
�62
, 0�x � 4t � 1
�4, �4��1, 3�
4 8−2
2
6
4
8
10−2
−4
y
1 2−1−2−3 3 4 5 6
2
4
5
6
3
1
y
f �x� � �x � 4�2 � 4f �t� � �2�t � 1�2 � 3
�2 ± �7, 0���4 ±�6, 0�x � 2x � �4
�2, 7���4, �6�
x4−2
2
4
8
6
10
2 106 8
y
x2
2
−8 −4
−2
−4
−6
y
h�x� � ��x � 2�2 � 7f �x� � �x � 4�2 � 6
�0, 0�, �6, 0��0, 0�, �2, 0�x � 3x � 1
�3, 9��1, �1�
x4
−28−2
2
4
8
6
10
2 10
y
x1−1
−2
−1−2−3
3
4
5
6
7
2 3 4 5 6
y
f �x� � ��x � 3�2 � 9g�x� � �x � 1�2 � 1
y
x−4 −3 −2
−4
−3
−2
1
2
3
4
2 3 4
y
x−3 −2 −1
−3
−2
−1
1
2
3
4
5
21 3 4 5
y
x−4 −3 −1
−3
−2
−1
1
2
3
5
1 3 4
y
x−4 −3 −1
−5
−2
−1
2
3
1 3 4
y
x−4 −3 −2
−4
−3
−2
−1
1
4
−1 1 2 3 4
y
x−4 −3 −2
−4
−3
−2
−1
1
3
4
−1 1 2 3 4
y
x−4 −3 −2
−4
−3
2
1
3
4
−1 1 2 3 4
y
x−4 −3 −2
−4
−3
−2
−1
2
3
4
−1 1 2 3 4
Precalculus with Limits, Answers to Review Exercises 28
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333202CB02_AN.qxd 1/1/70 09:37 AM Page 28
Precalculus with Limits, Answers to Review Exercises 29
(Continued)
9. 10.
Vertex: Vertex:
Axis of symmetry: Axis of symmetry:No x-intercept x-intercepts:
11. 12.
Vertex: Vertex:
Axis of symmetry: Axis of symmetry:
x-intercepts: No x-intercept
13. 14.
Vertex: Vertex:
Axis of symmetry: Axis of symmetry:
x-intercepts: x-intercepts:
15. 16.
17. 18.19. (a) (b)
(c)
20. (a) $12,000; $13,750; $15,000(b) Maximum revenue at $40; $16,000. Any price greater
or less than $40 per unit will not yield as muchrevenue.
21. 1091 units
22. 24 years old
23. 24.
25. 26.
27. 28.
29. Falls to the left, falls to the right30. Falls to the left, rises to the right31. Rises to the left, rises to the right32. Rises to the left, falls to the right33. odd multiplicity; turning point: 134. 0, odd multiplicity; even multiplicity; turning points: 235. odd multiplicity; turning points: 236. 8, odd multiplicity; 0, even multiplicity; turning points: 237. 0, even multiplicity; odd multiplicity; turning points: 238. odd multiplicity; 0, even multiplicity;
turning points: 3�1, 2,
53,
0, ±�3,�3,
�7, 32,
x6−2−4−6 2 4
4
8
6
y
x
2
1
1−2
5
−5
3
4
3 4 5 6 7
y
x−1−2−3 1 2 3 4 5 6
2
−2
−3
4
5
6
3
1
y
x
1
1 2 3−2−3
3
−1
−2
−3
y
x−1−2−3
2
1
1 2 3
3
−1
−2
−3
y
x
2
1
1 2 7−2
5
−3
−4
3
4
3 4 6
y
y
x20 21 22 23 24 25
22
23
24
25
26
27
Age of bride
Age
of
groo
m
x � 50, y � 50A � 100x � x2
y � 100 � x
x
y
f �x� �13�x � 2�2 � 3f �x� � �x � 1�2 � 4
f �x� �14�x � 2�2 � 2f �x� � �
12�x � 4�2 � 1
�2 ±�33
, 0��±�41 � 52
, 0�x � 2x � �
52
�2, �1���52, �41
12�
–6 –4 –2 4 6 8 10
2
4
6
8
10
12
14
x
y
x
4
−4
−2 2−4−6−8
−6
2
y
f �x� � 3�x � 2�2 � 1f �x� �13�x �
52�2
�4112
�±�41 � 52
, 0�x � �
12x � �
52
��12, 4���5
2, �414 �
x
8
10
12
2
−2−2
2 4 6−4−6−8
y
x
−2
−2 2−4−6−8
−4
−10
y
f �x� � 4�x �12�2
� 4h�x� � �x �52�2
�414
�3 ± 2�2, 0�x � 3x � �
12
�3, �8���12, 12�
x4 8
2
102−2
−2
−4
−6
−8
y
x−1−2−3 1 2 3
5
10
15
20
y
f �x� � �x � 3�2 � 8h�x� � 4�x �12�2
� 12
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333202CB02_AN.qxd 1/1/70 09:37 AM Page 29
(Continued)
39. (a) Rises to the left, falls to the right (b)(c) Answers will vary.(d)
40. (a) Rises to the right, falls to the left(b) (c) Answers will vary.(d)
41. (a) Rises to the right, rises to the left (b)(c) Answers will vary.(d)
42. (a) Falls to the left, falls to the right(b) (c) Answers will vary.(d)
43. (a) (b)44. (a) (b)45. (a) (b)46. (a) (b)
47. 48.
49. 50.
51.
52.
53.
54.
55. 56.57. (a) Yes (b) Yes (c) Yes (d) No58. (a) Yes (b) No (c) Yes (d) No59. (a) (b) 60. (a) (b) 061. (a) Answers will vary.
(b)(c)(d) 4(e)
62. (a) Answers will vary. (b)(c) (d)(e)
63. (a) Answers will vary. (b)(c)(d) 3, 4(e)
64. (a) Answers will vary. (b)(c) (d)(e)
65. 66. 67.68. 69. 70.71. 72. 73. �4 � 46i17 � 28i40 � 65i
��2 i3 � 7i�1 � 5i�1 � 3i3 � 5i6 � 2i
−6 12
−8
4
1, 2, 3, 5f �x� � �x � 1��x � 3��x � 2��x � 5��x � 1�, �x � 3�
−3
−10
5
40
�1,�2,f �x� � �x � 1��x � 4��x � 2��x � 3�
�x � 4��x � 1�,
−7 5
−100
50
�52, 3, �6f �x� � �2x � 5��x � 3��x � 6�
�2x � 5�, �x � 3�
−8 5
−60
80
�1,�7,f �x� � �x � 7��x � 1��x � 4�
�x � 1��x � 7�,
�3276�9�421
3x2 � 11x � 42x2 � 11x � 6
0.1x2 � 0.8x � 4 �19.5
x � 5
6x3 � 8x2 � 11x � 4 �8
x � 2
3x2 � 5x � 8 �10
2x2 � 1
x2 � 3x � 2 �1
x2 � 2
3x2 � 3 �3
x2 � 15x � 2
4
3�
29
3�3x � 2�8x � 5 �
2
3x � 2
� �0.509, � �1.211��2, �1, ��1, 0� �0.200, � 1.772��1, 0, �1, 2��4.479��5, �4��0.900��1, 0
y
x−4 −3 −1
−4
−3
−2
−1
2
3
4
1 3 4
( (3, 0 ( (3, 0−
(0, 0)
0, ±�3
y
x−4 −1−2
3
21 3 4
−15
−18
−21
(−3, 0)
(0, 0)
(1, 0)
�3, 0, 1
y
x−4 −3 −1
−4
−3
−2
−1
2
3
4
21 3 4
(−2, 0) (0, 0)
�2, 0
y
x−4 −3 −2
−4
−3
1
2
3
4
1 2 3 4
(−1, 0)
�1
Precalculus with Limits, Answers to Review Exercises 30
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Precalculus with Limits, Answers to Review Exercises 31
(Continued)
74. 75. 76. 77.
78. 79. 80. 81.
82. 83. 84. 4 85.
86. 0, 87. 88. 5, 8,89.
90.
91. 92. 6 93.94. 95. 96. 2,97.98.99. 100. 101.
102.103.104.105.106.
107. Two or no positive zeros, one negative zero108. One or three positive real zeros, two or no negative real zeros109–110. Answers will vary.111. Domain: all real numbers x except 112. Domain: all real numbers x except 113. Domain: all real numbers x except 114. Domain: all real numbers x115. Vertical asymptote:
Horizontal asymptote:116. Horizontal asymptote:117. Vertical asymptote:
Horizontal asymptote:118. Vertical asymptotes:
Horizontal asymptotes: None
119. (a) Domain: all real numbers x except (b) No intercepts(c) Vertical asymptote:
Horizontal asymptote:(d)
120. (a) Domain: all real numbers x except (b) No intercepts(c) Vertical asymptote:
Horizontal asymptote:
(d)
121. (a) Domain: all real numbers x except
(b) x-intercept:
y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
122. (a) Domain: all real numbers x except
(b) x-intercept:
y-intercept:
(c) Vertical asymptote:
Horizontal asymptote:
(d)
123. (a) Domain: all real numbers (b) Intercept:(c) Horizontal asymptote:
(d)
124. (a) Domain: all real numbers (b) Intercept:(c) Horizontal asymptote: y � 0
�0, 0�x
(0, 0)−3 −2 −1 2 3
−2
2
3
4
x
y
y � 1�0, 0�
x
−2 −1 1 4 5 6
−3
−2
3
4
5
x
(3, 0)
( (0, 32
y
y � 1
x � 2
�0, 32��3, 0�
x � 2
−8
−6
−4
−2
4
6
x2(−2, 0)
(0, 2)
y
y � �1
x � 1
�0, 2���2, 0�
x � 1
−3 −2 −1 1 2 3 4
−3
−2
1
2
3
4
x
y
y � 0x � 0
x � 0
−1 1 2
−3
−2
1
x
y
y � 0x � 0
x � 0
x � �2, �1y � 0
x � �3y � 2y � 0
x � �3
x � 6, 4x � �
13
x � �12
f �x� � �x � 3��x � 3��x � 4 � i ��x � 4 � i �±3, �4 ± i;
�x � 2 � 3i��4, 2 ± 3i; g�x� � �x � 4�2�x � 2 � 3i��2, 3, 6; g�x� � �x � 2��x � 3��x � 6�0, 1, �5; f (x� � x �x � 1��x � 5�0, 34, 1 ± i
�3, 12, 2 ± i2, ±4i4, ± ix 4 � x3 � 3x2 � 17x � 303x4 � 14x3 � 17x2 � 42x � 24
±25�3,�4, 3�2�5,
1, 853,�1,�1, �3, 6
±1, ±2, ±4, ±8, ±13, ±2
3, ±43, ±8
3
±1, ±3, ±5, ±15, ±12, ±3
2, ±52, ±15
2 , ±14, ±3
4, ±54, ±15
4
3 ± i�4, 6, ±2i±�6 i
8, 1�9,0, 2�14
±�71
4i
1 ± 3i±12
i±�33
i985
�8385
i
2113 �
113i17
26 �726 i23
17 �1017i9 � 20i
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333202CB02_AN.qxd 1/1/70 09:37 AM Page 31
(Continued)
(d)
125. (a) Domain: all real numbers x(b) Intercept:(c) Horizontal asymptote:(d)
126. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
127. (a) Domain: all real numbers x(b) Intercept:(c) Horizontal asymptote:(d)
128. (a) Domain: all real numbers x except (b) Intercept:(c) Vertical asymptotes:
Horizontal asymptote:
(d)
129. (a) Domain: all real numbers x except (b) x-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
130. (a) Domain: all real numbers x except (b) x-intercept:(c) Vertical asymptote:
Horizontal asymptote:(d)
131. (a) Domain: all real numbers x(b) Intercept: (c) Slant asymptote:(d)
132. (a) Domain: all real numbers x except (b) y-intercept:(c) Vertical asymptote:
Slant asymptote: y � x � 1x � �1
�0, 1�x � �1
1
x
−2
2
3
3
−3
1 2−1−2−3
y
(0, 0)
y � 2x�0, 0�
y
x
, 023( (
−1−2−3 2 3
2
y � 1.5x � �
12
�23, 0�
x � ±12
y
x−2−4−6−8 4 6 8
−2
−4
−6
−8
, 032( (
2
y � 2x � 0
�1.5, 0�
13x � 0,
−6 −4 4 6
4
6
x(0, 0)
y
y � 2x � ±2
�0, 0�x � ±2
x−2−4−6
2
6
−8
4
2 4
(0, 0)
y
y � �6�0, 0�
−3 −2 −1 2 3 4 5
1
3
5
6
7
x
(0, 4)
y
y � 0x � 1
�0, 4�x � 1
1 2
−2
−1
1
2
x(0, 0)
y
y � 0�0, 0�
−3
−2
−1
1
2
3
x1 2 3
(0, 0)
y
Precalculus with Limits, Answers to Review Exercises 32
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Precalculus with Limits, Answers to Review Exercises 33
(Continued)
(d)
133. (a) Domain: all real numbers x except (b) y-intercept:
x-intercepts:
(c) Vertical asymptote:
Slant asymptote:(d)
134. (a) Domain: all real numbers x except (b) x-intercepts:
y-intercept:(c) Vertical asymptote:
Slant asymptote:(d)
135. $0.50 is the horizontal asymptote of the function.
136. (a)
(b) $176 million; $528 million; $1584 million (or $1.584billion)
(c) No
137. (a)
(b)
(c)(d)
9.48 inches 9.48 inches138.
80.3 milligrams per square decimeter per hour
139. 140.
141. 142.
143. 144.145. 146.147. 4.9% 148. 9 days149. False. A fourth-degree polynomial can have at most four
zeros, and complex zeros occur in conjugate pairs.
150. False. The domain of is the set of all realnumbers.
151. Find the vertex of the quadratic function and write thefunction in standard form. If the leading coefficient is positive, the vertex is a minimum. If the leading coeffi-cient is negative, the vertex is a maximum.
152. Answers will vary. Sample answer:A polynomial of degree with real coefficients canbe written as the product of linear and quadratic factorswith real coefficients, where the quadratic factors have noreal zeros.Setting the factors equal to zero and solving for the variable can find the zeros of a polynomial function.To solve an equation is to find all the values of the variable for which the equation is true.
153. An asymptote of a graph is a line to which the graphbecomes arbitrarily close as increases or decreaseswithout bound.
x
n > 0
f �x� �1
x2 � 1
��, 0� � �2, ���4, �3 � �0, ���, 3� � �5, ���5, �1� � �1, ���, 0� � �0, 53���4, 0 � �4, ���, �3 � �5
2, ���43, 12�
00
100
90
�
04 32
200
4 < x <
�2x�2x � 7�
x � 4
Area � x�4x � 14x � 4 �
y �4x � 14x � 4
�x � 4�� y � 4� � 30
y
x
2 in.
2 in.
2 in. 2 in.
00
100
4000
y
x
, 043( (
−2−4−6 4 6−2
−6
2
4
(2, 0)
(0, −8)
y � x � 3
x �13
�0, �8��2, 0�, �4
3, 0�x �
13, �2
y
x(1, 0)
, 0
−1−2 2 3 4
−2
1
2
3
4
23( (
0, − 12( (
y � x �13
x �43
�23, 0�, �1, 0�
�0, �0.5�x �
43
x−2−4−6 62
4
4
y
(0, 1)
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333202CB02_AN.qxd 1/1/70 09:37 AM Page 33
Chapter Test (page 212)1. (a) Reflection in the x-axis followed by a vertical
translation(b) Horizontal translation
2.
3. (a) 50 feet
(b) 5. Yes, changing the constant term results in a verticaltranslation of the graph and therefore changes themaximum height.
4. Rises to the left, falls to the right
5. 6.
7.
Solutions:
8. (a) (b) 7 9.
10.
11.
12. 13.
14. -intercepts:
No -intercept
Vertical asymptote:
Horizontal asymptote:
15. -intercept:-intercept:
Vertical asymptote:Horizontal asymptote:
16. No -intercept-intercept:
Vertical asymptote:Slant asymptote:
17. 18.
−2−4−6−8 0 2 4 6
x
210−1−2−3−4−5 3x
32
x < �6 or 0 < x < 4x < �4 or x > 32
−8 −6 −4 2 4 6 8
−6
−4
2
4
6
8
10
x
(0, −2)
y
y � x � 1x � 1
�0, �2�yx
y
x−4−6−8 2 4
−2
−4
2
4
6
8
(−1.5, 0)
(0, 0.75)
y � 2x � �4
�0, 0.75�y��1.5, 0�x
−2 −1 1 2
−2
1
2
3
4
x(2, 0)(−2, 0)
y
y � �1
x � 0
y
��2, 0�, �2, 0�x
�2, 4, �1 ± �2 i�2, ±�5i
f �x� � x4 � 6x3 � 16x2 � 24x � 16
f �x� � x4 � 9x3 � 28x2 � 30x
2 � i�3 � 5i
14, ±�3
�4x � 1��x � �3 ��x � �3 �;
2x3 � 4x 2 � 3x � 6 �9
x � 23x �
x � 1
x2 � 1
t−1
−2
−3
−4
−5
−2−3−4 2
5
3 4 5
3
4
y
y � �x � 3� 2 � 6
Precalculus with Limits, Answers to Chapter Test 34
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Precalculus with Limits, Answers to Problem Solving 35
Problem Solving (page 215)1. Answers will vary.2. (a)
(b) (c) (d) (e)(f) (g)
3. 2 inches 2 inches 5 inches
4. False, the statement would be true if the 2 were replaced by
5. (a) and (b)
6. (a) less than (b) greater than
(c) less than (d)
(e) The values are the same.
(f)
7. (a)
(b)
8. (a) (b) (c)
9.
10. (i) d (ii) b (iii) a (iv) c
11. (a) As increases, the graph stretches vertically. Forthe graph is reflected in the x-axis.
(b) As increases, the vertical asymptote is translated.For the graph is translated to the right. For
the graph is reflected in the x-axis and is trans-lated to the left.
12. (a)
(b)
(c) The models are a good fit for the original data.(d)
The rational model is the better fit for the original data.(e) The reciprocal model should not be used to predict the
near point for a person who is 70 years old because anegative value is obtained. The quadratic model is abetter fit.
y2 � 3.861y1 � 1.125;
00
70
50
y2 ��134.82x � 59.93
00
70
50
y1 � 0.031x2 � 1.57x � 21.0
b < 0,b > 0,
�b�a < 0,
�a�
� a2 � b2
�a � bi ��a � bi� � a2 � abi � abi � b2i2�
134 �
217 i3
10 �110i1
2 �12 i
f �x� � ��x � 3�x 2 � 1 � �x3 � 3x 2 � 1
f �x� � �x � 2�x 2 � 5 � x3 � 2x 2 � 5
m tan � 4 since h � 0.
mh � 3, 5, 4.1;
mh � h � 4m3 � 4.1;
m2 � 3;m1 � 5;
y � �x2 � 5x � 4
f ��1�.
��
x � 3x � 6x � 10x � 3x � 6x � 6
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y 1 2 3 4 5
2 12 36 80 150y3 � y2
y 6 7 8 9 10
252 392 576 810 1100y3 � y2
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