College Algebra 9th txtbk

Student Answer Appendix
SA-9
77. Graphs of f and g Graph of m Graph of n
10
10
10
10
10
10
10
10
10
10
10
10
if 0 x 3,000
32 if 0 x 100
81. R(x) 83. E(x) 200
80 0.04x if 3,000 6 x 6 8,000
16 0.16x if x 7 100
180 0.04x if x 8,000
Discontinuous at x 8,000
E(5,750) $310, E(9,200) $548
E(x)
500
5,000
x
10,000
85. x 4 4 6 6 24 25 247 243 245 246
; f rounds numbers to the tens place.
f(x) 0 0 10 10 20 30 250 240 240 250
89. (A)
15 0 6 x 1
18 1 6 x 2
21 2 6 x 3
C(x) f
24 3 6 x 4
27 4 6 x 5
30 5 6 x 6
$30
$15
C(x)
91.
(B) No, since f (x) C(x) at x 1, 2, 3, 4, 5, or 6
0.03x if 0 x 10,000
T(x) 0.05x 200 if x 7 10,000 93.
y
1,000
0 1 2 3 4 5 6
x
0 x 19,890
T(x) 0.0535x
0.0705x 338.25 19,890 6 x 65,330
0.0785x 860.41 x 7 65,330
T(10,000) $535
T(30,000) $1,776.75
T(100,000) $6,989.60
24
x
Exercises 3-3
5. Domain: [0, ); Range: (, 0]
11. Domain: [2, 2]; range: [0, 4] 13. Domain: [2, 2]; range: [1, 3] 15. Domain: [0, 4]; range: [2, 2]
y
y
y
4
4
2
2
2
2
4
x
2 2
x
2 2
x
2