11
Precalculus with Limits, Answers to Section 11.1 1 Chapter 11 Section 11.1 (page 817) Vocabulary Check (page 817) 1. three-dimensional 2. -plane, -plane, -plane 3. octants 4. Distance formula 5. 6. sphere 7. surface, space 8. trace 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Octant IV 12. Octant VI 13. Octants I, II, III, and IV 14. Octants III, IV, VII, and VIII 15. Octants II, IV, VI, and VIII 16. Octants I, II, VII, and VIII 17. units 18. units 19. units 20. units 21. units 22. 5 units 23. units 24. units 25. 26. 27. 28. 29. isosceles triangle 30. isosceles triangle 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. Center: radius: 48. Center: radius: 4 49. Center: radius: 2 50. Center: radius: 2 51. Center: radius: 1 52. Center: radius: 53. Center: radius: 3 54. Center: radius: 1 55. Center: radius: 1 56. Center: radius: 3 57. 58. 59. 60. 2 2 4 4 6 x y z 4 4 2 (0, 1, 1) 4 6 x 2 + (y 1) 2 = 3 y x 2 2 2 z (2, 3, 0) (y 3) 2 + z 2 = 5 2 4 6 8 6 2 x y z (0, 3, 0) 10 4 6 6 8 2 (y + 3) 2 + z 2 = 25 x y (1, 0, 0) z (x 1) 2 + z 2 = 36 4 2 6 2 8 2 6 8 2 4 10 1 2 , 4, 1; 1 3 , 1, 0; 1 2 , 3 2 , 1; 1, 1 3 , 4; 23 0, 4, 3; 2, 0, 4; 3, 2, 0; 2, 1, 3; 0, 4, 0; 5 2 5 2 , 0, 0; x 1 2 2 y 1 2 z 4 2 61 4 x 3 2 2 y 2 z 3 2 45 4 x 2 y 5 2 z 9 2 16 x 3 2 y 7 2 z 5 2 25 x 2 2 y 1 2 z 8 2 36 x 2 y 4 2 z 3 2 9 x 3 2 y 4 2 z 3 2 4 x 3 2 y 2 2 z 4 2 16 9, 7 2 , 3 2 2.5, 2, 6 9 2 , 9 2 , 13 2 1, 0, 5.5 1, 6, 2 0, 1, 7 3 2 , 7 2 , 1 2 3 2 , 1, 2 3, 3, 42 ; 6, 6, 210 ; 3 2 2 2 13 2 3 2 6 2 35 2 214 2 6 2 62 2 25 2 3 2 29 2 113 110 114 13 29 213 65 0, 2, 8 10, 0, 0 6, 1, 1 3, 3, 4 y x 3 2 4 6 5 1 1 2 3 4 5 (4, 0, 4) z (0, 4, 3) 4 3 5 6 3 4 5 y x 1 2 4 1 2 3 2 3 4 5 1 2 3 2 3 4 3 4 5 (3, 1, 0) (4, 2, 2) z y x 1 2 4 3 3 2 1 2 4 3 4 5 (3, 0, 0) (3, 2, 1) z 2 3 4 5 y x 5 4 3 2 2 2 3 1 3 5 2 4 1 2 3 4 5 z (1, 2, 1) (2, 1, 3) 2, 3, 0 C: 2, 1, 2; B: 6, 2, 3; A: 3, 0, 2 C: 1, 3, 2, B: 1, 4, 4, A: x 1 x 2 2 , y 1 y 2 2 , z 1 z 2 2 yz xz xy Copyright © Houghton Mifflin Company. All rights reserved. 332522CB_1100_AN.qxd 4/4/06 5:30 PM Page 1

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Precalculus with Limits, Answers to Section 11.1 1

Chapter 11Section 11.1 (page 817)

Vocabulary Check (page 817)1. three-dimensional2. -plane, -plane, -plane 3. octants

4. Distance formula 5.

6. sphere 7. surface, space 8. trace

1.2.3. 4.

5. 6.

7. 8. 9.

10. 11. Octant IV 12. Octant VI

13. Octants I, II, III, and IV

14. Octants III, IV, VII, and VIII

15. Octants II, IV, VI, and VIII

16. Octants I, II, VII, and VIII

17. units 18. units 19. units

20. units 21. units 22. 5 units

23. units 24. units

25.

26. 27.

28. 29. isosceles triangle

30. isosceles triangle 31.

32. 33. 34.

35. 36. 37.

38. 39.

40.

41.

42.

43.

44.

45.

46.

47. Center: radius:

48. Center: radius: 4

49. Center: radius: 2

50. Center: radius: 2

51. Center: radius: 1

52. Center: radius:

53. Center: radius: 3

54. Center: radius: 1

55. Center: radius: 1

56. Center: radius: 3

57. 58.

59. 60.

2

2

4

46x

y

z

−4 −4−2 (0, 1, −1)

−4

−6x2 + (y − 1)2 = 3y

x

2

2 2

z

(−2, 3, 0)

(y − 3)2 + z2 = 5

2

4

6

86

2

x

y

z

(0, −3, 0)

−10

−4

−6

−6−8

−2

(y + 3)2 + z2 = 25x

y(1, 0, 0)

z

(x − 1)2 + z2 = 36

4

2

6

2

8

−2

−6−8

−2

4

10

�12, 4, �1�;

�13, �1, 0�;

�12, 32, 1�;

�1, 13, 4�;2�3�0, 4, 3�;

��2, 0, 4�;

�3, �2, 0�;

�2, �1, 3�;

�0, 4, 0�;

52�5

2, 0, 0�;�x �

12�2

� �y � 1�2 � �z � 4�2 �614

�x �32�2

� y2 � �z � 3�2 �454

x2 � �y � 5�2 � �z � 9�2 � 16

�x � 3�2 � �y � 7�2 � �z � 5�2 � 25

�x � 2�2 � �y � 1�2 � �z � 8�2 � 36

x2 � �y � 4�2 � �z � 3�2 � 9

�x � 3�2 � �y � 4�2 � �z � 3�2 � 4

�x � 3�2 � �y � 2�2 � �z � 4�2 � 16�9, �72, �3

2��2.5, 2, 6���9

2, 92, 132 ��1, 0, 5.5�

�1, 6, �2��0, �1, 7��32, 72, 12�

�32, �1, 2�3, 3, 4�2;

6, 6, 2�10;32 � 22 � ��13 �2

32 � 62 � �3�5 �2�2�14�2� ��6�2

� ��62�2

�2�5�2 � 32 � ��29�2

�113�110

�114�13

�292�13�65

�0, 2, 8�

�10, 0, 0��6, �1, �1���3, 3, 4�

y

x

32

−4

65

1

1

2345

(4, 0, 4)

z

(0, 4, −3)

−4 −3 5 6

−3−4−5

y

x

12

4

1

2

3

−2

−3

−4

−5

1 2 3−2

−3−4

−3−4−5

(3, −1, 0)

(−4, 2, 2)z

y

x

12

4

3

321−2

−4

−3−4−5

(3, 0, 0)

(−3, −2, −1)

z

−2

−3

−4

−5

y

x

5432−2

−2

−3

1

3

5

2

4

1

2

3

4

5

z

(−1, 2, 1)(2, 1, 3)

��2, 3, 0�C:�2, �1, 2�;B:�6, 2, �3�;A:��3, 0, �2�C:�1, 3, �2�,B:��1, 4, 4�,A:

�x1 � x2

2,

y1 � y2

2,

z1 � z2

2 �yzxzxy

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(Continued)

61. 62.

63. 64. 65.

66. (a)(b) trace:

trace:These traces would form circles.

(c) trace:This trace would form a circle.

(d) trace (e) trace67. False. is the directed distance from the plane to 68. False. The trace could also be a point or may not exist.69. 0; 0; 070. No, the graph of the equation is a

plane.71. A point or a circle (where the sphere and the plane meet)72. A straight line in the -plane73.

74. 75.

76. 77.

78. 79.

80. 81.

82. 83.

84. 85. 86. 2

87. 1, 2, 6, 15, 31First differences: 1, 4, 9, 16Second differences: 3, 5, 7Neither

88.

First differences:

Second differences: 0, 0, 0

Linear

89. 2, 5, 8, 11

First differences: 3, 3, 3, 3

Second differences: 0, 0, 0

Linear

90.

First differences:

Second differences:

Quadratic

91.

92.

93.

94.

95.

96.

97.

98.�y � 5�2

16�

�x � 3�2

9� 1

�x � 6�2

4�

y2

32� 1

x2

45�4�

�y � 3�2

81�4� 1

�x � 3�2

9�

�y � 3�2

4� 1

�x � 2�2 � �20� y � 5�

�y � 1�2 � �12�x � 4�

�x � 3�2 � � y � 6�2 � 81

�x � 5�2 � �y � 1�2 � 49

�2, �2, �2

�4, �6, �8, �10

4, 0, �6, �14, �24

�1,

�1, �1, �1, �1

0, �1, �2, �3, �4

�7�149, 325.01�

�41, 51.34��5, 116.57�

3�2, 7�

4x � �

5 ± �894

y � �1 ± �10

2x � �

3 ± �132

x �5 ± �5

2z �

7 ± 5�52

v � �3 ± �17

2�7, 16, 12�

�x2, y2, z2� � �2xm � x1, 2ym � y1, 2zm � z1�xy

yz-

ax � by � cz � 0

xy-P.xy-z

xy-yz-

x2 � y2 � 39632xy-

y2 � z2 � 39632yz-x2 � z2 � 39632;xz-

x2 � y2 � z2 � 39632

x2 � y2 � z2 �1652

4�4, 4, 8��3, 3, 3�

x

y2

4

−6

−4

−2 −2

−42

z

yx

2 233

4455

5

6

z

Precalculus with Limits, Answers to Section 11.1 2

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Precalculus with Limits, Answers to Section 11.2 3C

opyr

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. All

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eser

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Section 11.2 (page 825)

Vocabulary Check (page 825)1. zero 2.3. component form 4. orthogonal 5. parallel

1. (a) 2. (a)(b) (b)

3. (a) (b) (c)

4. (a) (b) (c)

5. (a) (b)

(c) (d)

6. (a) (b)

(c) (d)

7. 8.

9. 10. 11.

12. 13. 14. 15. 16.

17. (a) (b)

18. (a)

(b)

19. 20. 28 21. 0 22. 0 23.

24. 25. 26.

27. Parallel 28. Neither 29. Orthogonal

30. Parallel 31. Not collinear 32. Collinear

33. Collinear 34. Not collinear 35.

36. 37. 38.

39. 40.

41. or

42. or

43. 226.52 newtons, 202.92 newtons, 157.91 newtons

44. (a)

(b)

(c)

Horizontal asymptote:Vertical asymptote:The minimum tension in each cable is 8; the minimumcable length is 18.

(d) 30 inches

L � 18T � 8

0 1000

30

T = 8

L = 18

T �8L

�L2 � 182, L > 18

��5�3, 0, 5�5�3, 0, 5�0, 2�2, �2�2�0, 2�2, 2�2

±�6±3�14

14

�112 , 32, 72��6, 52, �7

4��10, �5, 2��3, 1, 7�

65.47�109.92�49.80�

124.45��4

��134134

��3i � 5j � 10k�

�134134

��3i � 5j � 10k�

��7474

�8i � 3j � k��7474

�8i � 3j � k�

�14�34�41�74�29

9�2z � �0, �1, 0z � � 12, 6, 32

z � ��7, 19, 13z � ��3, 7, 6

y

x

12

34

2

1

3

4

5

6

321 4 5−2

−3−4

−2

−3

z52

− , 5, 5

y

x

1

2

2

1

21−1

−2

−1

−2

−2

z

12

− , 1, 1

y

x

12

34

2

1

3

4

321 4−2

−3−4

−3

−2

−4

−3−4

z ⟨−2, 4, 4⟩

y

x

2

1

3

4

21

−3−4

−3

−2

−4

−3−4−5−6

z

⟨1, −2, −2⟩

y

x

12

34

2

3

4

321 4−2

−3−4

−3

−2

−4

−3−4

z

⟨0, 0, 0⟩

y

x

12

34

2

1

3

4

5

32 4−2

−3

−2

−3−4

z

32

, 32

, 92

y

x

12

34

2

3

4

321 4−2

−3−4

−3

−4

−3−4

z

⟨−1, −1, −3⟩y

x

12

34

1

2

3

4

5

6

31 4−2

−2

−3−4

z

⟨2, 2, 6⟩

�6767

�7, �3, �3�67�7, �3, �3

�1133

�7, �5, 53�11�7, �5, 5

y

x

3

12

34

−2

−3−2

−1

−4

−3−4

23

4

2

−4

1

−2

−3

z

(0, 0, −4)y

x

3

2

1

1

−1

−2−3

−2−3

12

3

23

z

(−2, 3, 1)

�0, 0, �4��2, 3, 1

v � v1i � v2 j � v3k

20 25 30 35 40 45 50

18.4 11.5 10 9.3 9.0 8.7 8.6T

L

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(Continued)

45. True 46. True

47. The angle between u and v is an obtuse angle.

48. A line

49. (a) (b)

50. (a) (b)

51. (a) (b)

52. (a) (b)y � 4�t � 1�3y � 4t 3

x � t � 1x � ty � t 2 � 2t � 7y � t 2 � 8x � t � 1x � t

y �2

t � 1y �

2t

x � t � 1x � t

y � 3t � 1y � 3t � 2

x � t � 1x � t

Precalculus with Limits, Answers to Section 11.2 4

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Precalculus with Limits, Answers to Section 11.3 5

Section 11.3 (page 832)

Vocabulary Check (page 832)1. cross product 2. 0 3.4. triple scalar product

1. 2.

3. 4.

5. 6. 7.

8. 9.

10. 11. 12.

13. 14.

15. 16.

17.

18. 19.

20. 21. 1 22. 3 23.24. 25. 14 26.27. (a) and is parallel to

and is parallel to (b) Area is (c) The dot product is not 0 and therefore the parallelo-

gram is not a rectangle.28. (a) and is parallel to

and is parallel to (b) Area is

(c) The dot product is not 0 and therefore the parallelo-gram is not a rectangle.

29. 30. 31. 32.

33. 34. 6 35. 2 36. 6 37. 2

38. 9 39. 12 40. 16 41. 84 42. 3

43. (a)

(b)

44. foot-pounds

45. True. The cross product is not defined for two-dimensionalvectors.

46. False. The cross product is not commutative.

47. The magnitude of the cross product will be four times aslarge.

48. Answers will vary. 49. 50. 51.

52. 53. 54. 55. 56.

57.

The minimum value of is 0 and found at point The maximum value of is 52 and found at point

58.

The minimum value of is 46 and found at the point There is no maximum value of on this region.z

�3, 4�.z

x

y

−2 2 4 6 8

−2

2

4

6

8

�6, 4�.z�0, 0�.z

x

y

−2 2 4 6 8

−2

2

4

6

8

�3�1��32

�12

��32

�12��3�

12

160�3

T �p2

cos 40�

�16

8�512�42903�11

3�132

�AB\

� AC\

� � 2�83.AC

\

� �5, 4, 1.BD\

� �5, 4, 1CD

\

� �1, 2, 3.AB\

� �1, 2, 3

�AB\

� AD\

� � 6�10.BC

\

� ��3, 4, 4.AD\

� ��3, 4, 4DC

\

� �1, 2, �2.AB\

� �1, 2, �23�30�213

�80623i �

23 j �

13k

�22

�i � j��4291287

�10i � 25j � 56k�

�76027602

��71i � 44j � 25k�

17

��6i � 3j � 2k��1919

�i � 3j � 3k�

�2i � j � k�i � 2j � k

2j �29k�18i � 6j�

32i �

32 j �

32k

�7i � 13j � 16k��7, 37, �20�0, 42, 0��29, 36, �38�3, �3, �3

y

x

1

22

1

2

(0, 1, 0)

z

−2

−1

−2

−2

−1

−1

y

x

1

22

1

2

z

−2−2

−2

−1

−1

(0, −1, 0)

j�j

y

x

1

22

1

2

z

−2

−2

−2

−1

−1

(−1, 0, 0)

y

x

1

2

1

−1

2

z

−2

−2

−2

−1

−1

−1

(0, 0, −1)

�i�k

�u � �v � sin �

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15 20 25 30 35 40 45

5.75 7.66 9.58 11.49 13.41 15.32 17.24T

p

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Section 11.4 (page 841)

Vocabulary Check (page 841)

1. direction, 2. parametric equations

3. symmetric equations 4. normal5.

1. (a)

(b)

2. (a)

(b)

3. (a)

(b)

4. (a)

(b)

5. (a)

(b)

6. (a)

(b)

7. (a)

(b)

8. (a)

(b)

9. (a)

(b)

10. (a)

(b)

11. (a)(b) No symmetric equations

12. (a)(b) No symmetric equations

13. (a)

(b)

14. (a)

(b)

15. 16.

17. 18.19.20.21.22.23.24.25.26.27. 28.29. Orthogonal 30. Parallel31. Orthogonal 32. Parallel33. (a) (b)34. (a) (b)35. (a) (b)

36. (a) and (b). The two planes are parallel because the nor-mal vector is a scalar multiple of the normal vector and the planes do not intersect.

37. 38.

39. 40.

y

x

32

6

32

−1 −1−2

−2

6

23

45

6

(0, 5, 0)

(0, 0, 5)

z

y

x

32

4

4

6

3

−1−2

564

32

56

(0, 2, 0)(4, 0, 0)

z

−1−2

y

x

3456

232

34

56

(0, 0, 1)

(2, 0, 0)

z

−2−4

−5

(0, −4, 0)

y

x

34

4

56

2

−2

56

23

(0, 0, 2)

(0, 3, 0)

(6, 0, 0)

z

n2��3, �6, 3,n1�2, 4, �2

x � 6t � 1, y � t, z � 7t � 177.8�

x � �5t �32, y � �t �

16, z � 2t66.9�

x � �t � 2, y � 8t, z � 7t60.7�

7x � y � 11z � 5 � 0y � 5 � 02x � 11y � 4z � 5 � 06x � 2y � z � 8 � 0�x � y � 4z � 7 � 0�3x � 9y � 7z � 0�x � y � 2z � 12 � 0�x � 2y � z � 2 � 0�3y � 5z � 0�2x � y � 2z � 10 � 0

z � 3 � 0x � 2 � 0

y

(5, 1, 5)

z

x

6

4

2

2

−6

−4−6

24

64

6y

(0, 2, 1)

z

x

3

2

1

1

−1

−2−3

−2−3

12

32

3

x � 39

�y � 3�13

�z � 4�12

x � �3 � 9t, y � 3 � 13t, z � 4 � 12t

2x � 13

� �2y � 4

5�

2z � 1�1

x � �12

� 3t, y � 2 � 5t, z �12

� t

x � 2, y � �1 � 2t, z � 5 � 8t

x � 3 � 4t, y � 1, z � 2 � 3t

x � 2�1

�y � 3�8

�z � 1

4

x � 2 � t, y � 3 � 8t, z � �1 � 4t

x � 34

�y � 8�10

� z � 15

x � �3 � 4t, y � 8 � 10t, z � 15 � t

x � 28

�y � 3

5�

z12

x � 2 � 8t, y � 3 � 5t, z � 12t

x � 2�1

�y4

�z � 2�5

x � 2 � t, y � 4t, z � 2 � 5t

x � 13

�y

�2� z � 1

x � 1 � 3t, y � �2t, z � 1 � t

x � 22

�y � 3�3

� z � 5

x � 2 � 2t, y � �3 � 3t, z � 5 � t

x � 54

�z � 10

3, y � 0

x � 5 � 4t, y � 0, z � 10 � 3t

x � 43

�y � 1

8�

z�6

x � �4 � 3t, y � 1 � 8t, z � �6t

x � 33

�y � 5�7

�z � 1�10

x � 3 � 3t, y � �5 � 7t, z � 1 � 10t

x �y2

�z3

x � t, y � 2t, z � 3t

a�x � x1� � b�y � y1� � c�z � z1� � 0

PQ\

t

Precalculus with Limits, Answers to Section 11.4 6

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Precalculus with Limits, Answers to Section 11.4 7

(Continued)

41. 42.

43. 44. 45. 46.

47. (a) (b) The approximations are verysimilar to the actual values of

(c) Answers will vary.

48.

49. False. Lines that do not intersect and are not in the sameplane may not be parallel.

50. True

51. Parallel. is a scalar multiple of

52. (a) Sphere:

(b) Two planes:

53. 54.

55. 56.

57. 58.

59.

60. r �1

sin � � 2 cos �

r � 5 csc �

r � 4 cos �r � 7

3x2 � 4y2 � 2x � 1 � 0x2 � y2 � 3x � 0

y � �xx2 � y2 � 100

4x � 3y � z � 10 ± 2�26

�x � 4�2 � �y � 1�2 � �z � 1�2 � 4

��15, 27, �30.�10, �18, 20

89.1�

z.

3�14

�3�14

144�6

�2�6

3

�66

89

xy

2

2

−2

−2

−4

−6

6

z

(6, 0, 0)(0, 0, −2)

x y6

−1−2 −2

−1

−7−6

54

3

65

4

z

(0, 0, −6)

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

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Year

1999 7.85

2000 7.70

2001 7.50

2002 7.34

2003 7.22

z

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Review Exercises (page 844)1. 2.

3. 4.

5. 6.

7.

8.

9.

10. 11. 12.

13.

14.

15.

16.

17. Center: radius: 3

18. Center: radius: 2

19. (a) (b)

20. (a) (b)

21. (a)

(b)

(c)

22. (a) (b)

(c)

23. (a) (b)

(c)

24. (a) (b)

(c)

25. 26. 0 27. 1 28. 29.

30. 31. Parallel 32. Orthogonal

33. Not collinear 34. Collinear

35. 159.1 pounds of tension115.6 pounds of tension115.6 pounds of tension

36. 106.1 pounds of tension77.1 pounds of tension77.1 pounds of tension

37. 38.

39. 40.

41.

42. 43. 75 44. 48

45. (a)

(b)

46. (a)

(b)x5

�y � 10

20�

z � 3�3

x � 5t, y � �10 � 20t, z � 3 � 3t

x � 14

�y � 3

3�

z � 5�6

x � �1 � 4t, y � 3 � 3t, z � 5 � 6t

Area � �8 � 2�2 2.83

Area � �172 � 2�43 13.11

j�71�7602

7602i �

22�76023801

j �25�7602

7602k

�15, 25, �105��10, 0, �10C:B:A:C:B:A:

47.61�

90��5�9

��19539

, �11�195

195,

7�195195

�195�5, �11, 7

��2�18537

, 6�185

185,

7�185185

�185��10, 6, 7

���35

7,

3�3535

, �3535 �35��5, 3, 1

��3333

, 4�33

33,

�4�3333

�33

�1, 4, �4

2

4

6

x

y

z(y − 1)2 + z2 = 5

(−2, 1, 0)

2

4

64x

y

z

(−2, 1, 0)

(x + 2)2 + (y − 1)2 = 9

2

2

4

4 42

6x

y(0, 3, 0)

z

(y − 3)2 + z2 = 16

−2 −2

2

2

4

4 46x

y

(0, 3, 0)

z

x2 + z2 = 7

−4−2

�5, �3, 2�;

�2, 3, 0�;

x2 � �y � 4�2 � �z � 1�2 �2254

�x � 1�2 � �y � 5�2 � �z � 2�2 � 36

�x � 3�2 � �y � 2�2 � �z � 4�2 � 16

�x � 2�2 � �y � 3�2 � �z � 5�2 � 1

��6, �6, �2��1, 2, �9��4, 0, �1�

�132 , 2, 5�

��29�2� ��13�2

� ��42�2

�29, �13, �42

��29�2� ��38�2

� ��67�2

�29, �38, �67

�61�41

�0, �7, 0���5, 4, 0�

y

x

12

34

1

2

−2

−3

3

4

5

31 2−2

−3−4

−3−4

z

(0, 0, 5)

(2, 4, −3)

y

x

12

34

1

2

3

−2

−3

−4−5

(5, −1, 2)

(−3, 3, 0)

z

1 2 3

−2

−3

−4

−5

Precalculus with Limits, Answers to Review Exercises 8

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Precalculus with Limits, Answers to Review Exercises 9

(Continued)

47. (a) (b)

48. (a)

(b)

49. 50.

51. 52.

53.

54.

55.

56.

57. 58. 59. 60.

61. False. 62. True. See page 831.

63–66. Answers will vary.

u � v � ��v � u�

6�147

�11055

�66

�110110

x

y

(0, 0, −4)

(0, 3, 0)1 21

−1

−2

43

2

−2

−3

−1

1

z

x

y

(3, 0, 0)

1 21

−2 −1

3

3

4

1

−1

−2

2

z

(0, 0, −2)

y

x

24

2

4

2

4

(1, 0, 0)

z

−4

−4

−2

(0, 0, −1)

(0, −5, 0)

x

y

(0, 0, 2)

(2, 0, 0)1 1

2

3

1

−2

z

(0, −3, 0)

�x � y � 2z � 12 � 0z � 2 � 0

�2y � 5z � 14 � 0�2x � 12y � 5z � 0

x � 3 � y � 2 � z � 1

x � 3 � t, y � 2 � t, z � 1 � t

x�2

�y

5�2� zx � �2t, y �

52

t, z � t

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Chapter Test (page 846)1.

2. No. 3.4.

5.6. (a) (b) 84 (c) 7.8. (a)

(b)

9. Neither 10. Orthogonal11. is parallel to

is parallel to

12. 13. 200

14.

15.

16. 17. 88.5�8

�14�

4�147

y

x

4

810

2

4

6

−6

−8

−10

2 4 6

−6

−10

(0, −10, 0)

(0, 0, −5)

(2, 0, 0)

z

y

x

1

65

1

3

4

21 4−2

−3

−3−4

z

(0, 0, 3)

(6, 0, 0)

(0, 4, 0)

27x � 4y � 32z � 33 � 0Area � 2�230

BD\

� �1, �3, 3.AC\

CD\

� �4, 8, �2.AB\

x � 8�2

�y � 2

6�

z � 5�6

x � 8 � 2t, y � �2 � 6t, z � 5 � 6t46.23��0, 62, 62�194

v � ��12, 5, �5u � ��2, 6, �6,

4

4

6

8

6

2

8

12

y

x sphere

z

−4

−8−10

−4−2

xz-trace

�x � 7�2 � �y � 1�2 � �z � 2�2 � 19�7, 1, 2���76�2

� ��102�2 ��194�2

y

x

24

2

−4

4

z

−2

−4

(−2, −2, 3)

(5, −2, 3)

Precalculus with Limits, Answers to Chapter Test 10

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Precalculus with Limits, Answers to Problem Solving 11

Problem Solving (page 849)1. (a)

(b) Answers will vary.(c)(d) Answers will vary.

2. Sphere of radius 4 centered at 3. Answers will vary. See online website.4. Answers will vary.5. (a) Right triangle (b) Obtuse triangle

(c) Obtuse triangle (d) Acute triangle6.

7. 8–11. Proof

12. (a)

(b)(c) This is what should be expected. When

the pipe wrench is horizontal.

13. (a)(b)

(c) when

(d)

(e) The zero is the angle making parallelto

14. Proof

15. (a) when

(b)

(c) The distance between the two insects appears to lessenin the first 3 seconds but then begins to increase withtime.

(d) The insects get within 5 inches of each other.

16. (a) (b)

17. (a) (b)

18. (a)

(b)

The minimum is at

(c) Yes, there are slant asymptotes. Using we havethe slant asymptotes

y � ±�105

21�s � 1�.

s � x,

s � �1.D 2.2361

−11

−4

10

10

D ��PQ

\

� u ��u�

���7 � s�2 � ��6 � 2s�2 � 25

�21

D � �5D �3�2

2

D ��53

D ��149�17

��2533

17

−1 110

20

t � 0.d � �70

F.AB

\

� 141.34�;

� 51.34�

� � 30�.�AB\

� F � � 298.2

−300

0 180

400

�AB\

� F � � 25�10 sin � � 8 cos ��F � �200�cos �j � sin �k�AB

\

� �54 j � k,

� � 90�,� � 90�.540�2 763.68

00

180

1440

1080 sin �

�F � � 860.0 lbsF3 � ��5�3, 5, �40

F2 � �5�3, 5, �40,F1 � �0, �10, �40,

�x1, y1, z1�

a � b � 1

y

x

3

2

1

1

−1

−2−3

−2−3

23

23

z

uv

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