
9. 13 11. (3,27/2)
13. circle; axes of symmetry: x 5 1, y 521; radius:
ffiffiffi
2
p
15. ellipse; axes of symmetry: x 521, y 5 2
17. y 5 3x 2 6
19. y 52x 2 4
21. y 526(x 1 2) 1 1
23. y 5 2(x 1 2) 1 1
25. x/4 1 y/(23) 5 1
27. x/(3/2) 1 y/3 5 1
29. (2, 3)
31. (21,28) and (4, 7)
33. (2N,N)
35. (2N,5),(5,N)
37. (2N, 22),(22,N)
39. [25, 23),(23,
3),(3, 5]
41. 1/2, 2/3, 3/4, 4/5, 5/6
43. 4, 8, 14, 24, 42
45. 7, 15, 31, 63, 127
47. 16 49. 41
51. 4x 1 12
ffiffiffi
x
p
1 9
53. 2x
2
/(2 1 x
2
)
55. 2x
4
1 4x
2
1 5
57. 2
ffiffiffiffiffiffiffiffiffiffiffi
1 1 x
p
1 3
59. 2(3x 1 4)/(2x 1 3)
61. T 5 [1/5, 1/2]; f
21
(t) 5 1/t 2 1
63. T 5 ½ 2; 5; f
21
ðtÞ521 1
ffiffiffiffiffiffiffiffiffiffi
t 2 1
p
65. Onto but not one-to-one
67. One-to-one but not onto
69. Translate left 2 units, down 1
71. Translate right 3 units, down 9
73. The line segment from (21/3, 0) to (0, 1/2)
75. The line segment from (1, 0) to (0, 1)
77. sinðAÞ5 3=
ffiffiffiffiffi
13
p
; cosðAÞ5 2=
ffiffiffiffiffi
13
p
; tanðAÞ5 3=2;
cotðAÞ5 2=3; secðAÞ5
ffiffiffiffiffi
13
p
=2; cscðAÞ5
ffiffiffiffiffi
13
p
=3
79. sinðAÞ5 1=
ffiffiffiffiffi
10
p
; cosðAÞ5 3=
ffiffiffiffi
ffi
10
p
;
tanðAÞ5 1=3; cotðAÞ5 3; secðAÞ5
ffiffiffiffiffi
10
p
=3; cscðAÞ5
ffiffiffiffiffi
10
p
81. sinðα 1 π=2Þ5 5=13; cosðα 1 π=2Þ5212=13;
tanðα 1 π=2Þ525=12; cotðα 1 π=2Þ5212=5;
secðα 1 π=2Þ5213=12; cscðα 1 π=2Þ5 13=5
83. 2 85. 22
ffiffi
ffi
2
p
87. 3
ffiffiffi
7
p
=8 89. 224/7
Section 2.1
1. 5 3. 57 5. 21
7. 24 9. 10 11. 21/14
13. Does not have a limit.
15. lim
x-2
f ðxÞ522
17. lim
x-5
f ðxÞ5 7
19. 0.01 21. 0.002 23. 0.2 25. 0.0019
27. lim
x-2
2
f ðxÞ5 0 6¼ 4 5 lim
x-2
1
f ðxÞ
29. a. The domains of g, f, h, and k are, respectively,
fx 2 R : x 6¼ 1g; R; R; and R: b. f and h
c. lim
x-1
gðxÞ5 lim
x-1
f ðxÞ5 lim
x-1
hðxÞ5 lim
x-1
kðxÞ5 2
31. a. The domains of f, g, k, and h are, respectively, R; R; R;
and fx 2 R : x 6¼ 0g: b. f and k
c. lim
x-0
gðxÞ¼lim
x-0
f ðxÞ¼lim
x-0
hðxÞ¼lim
x-0
kðxÞ¼0
33. lim
x-0
1
HðxÞ5 1; lim
x-0
2
HðxÞ5 0; lim
x-0
HðxÞ does not
exist
35. 3.28 3 10
23
37. a. Does not exist. b. 0 c. 1 d. 21
39. See Figure for Exercise 41, Section 1.4;
lim
x-n
1
bxc5 1 1 lim
x-n
2
bxc 6¼ lim
x-n
2
bxc
41. a. 3 b. 2.5 c. 2.1 d. 2 1 h e. 2
43. a. 4 b. 0.1 c. 0.01 d. ε
45. a. 8 b. 0.1 c. 0.01 d. ε
47. 6 1 h;6
49. h 1 4; 4
51. 0
53. |x 2 2| , 0.0095
1.010
1.005
1.000
0.995
0.990
0.985
2.0001.995 2.005
f (x) 4x
2
0.0095 0.0095
e 0.01
e 0.01
A-12 Answers to Selected Exercises