College Algebra 9th txtbk

SA-18
Student Answer Appendix
17. P(x) [x (2 3i)][x (2 3i)](x 4) 2 ; degree 4
87. (A) 1 2 13
2 i, 1 2 13
2 i (B) 3
91. No, because P(x) is not a polynomial with real coefficients (the coefficient of x is the imaginary number 2i ).
Exercises 4-4
15. Domain: all real numbers except 0; x intercept: 3 17. Domain: all real numbers except 2; x intercept: 6
19. Domain: all real numbers; x intercepts: 4, 1 21. Domain: all real numbers except 6; x intercepts: none
23. Vertical asymptote: x 2; horizontal asymptote: y 5 25. Vertical asymptotes: x 4, x 4; horizontal asymptote: y 0
27. Vertical asymptote: x 0; horizontal asymptote: none 29. Vertical asymptotes: x 3, x 0; horizontal asymptote: y 3 2
37. The graph of f is the same as the graph of g except that f has a hole at (2, 1 6).
39. y
41. y
43. y
45.
y
10
5
5
5
10 10
x
5
5
x
5 5
x
5 5
x
10
5
5
5
47. y
49. y
51.
y
5
5
10
5 5
x
5 5
x
10
10
x
5
10
53.
(2x 5)(x 10) 100
f (x) 3(x2 1)(x 2 4)
55. f (x)
x 4 1
x 10
73. Vertical asymptote: x 1; oblique asymptote: y 2x 2
77. Vertical asymptote: x 0; oblique asymptote: y 2x 3
79. y
81. y
83.
y
5
5
5 5
x
5 5
x
5 5
x
5
5
Vertical asymptote: x 0 Vertical asymptote: x 2 Vertical asymptote: x 0
Oblique asymptote: y x Oblique asymptote: y 1 2x 1 Oblique asymptote: y 1 4x
85. Domain: x 2, or (, 2) (2, ); f (x) x 2 87. Domain: x 2, 2 or (, 2) (2, 2) (2, ); r(x) 1
x 2
y
y
5
5
5
5 5
x
5
x
5
89. As t S , N S 50 91. As t S , N S 5
N
N
50
50
5
Vertical asymptote: x 2
Horizontal asymptote: y 0
25
25
0
25
50
t
0
25
50
t