3. Evaluate the expression –x2 + 1 for x = 5.
A) 26
B) –24
C) 24
D) –20
4. Evaluate the expression x3 – 2x2 – x + 9 for the indicated value of x.
(a) x = –5 (b) x = 2 (c) x = –1
5. True or False: The following relation is a function.
The number of miles driven each day for a five-day trip. Let an ordered pair be given in the form (day, miles).
6. True or False: The following relation, given as a table of values, is a function.
x y
0 0
–1 3
0 4
3 2
10. Use the table to find g(0).
x g(x)
–9 –78
0 3
2 –1
5 –22
A) 3
B) –22
C) –1
D) –78
11. Use the table to find j(–1).
x j(x)
-2 5
-1 0
0 4
1 7
14. Let f(x) = 4x + 3 and g(x) = –6x + 9. Find (f + g)(x).
A) 2x + 6
B) –2x + 12
C) 10x + 12
D) –2x + 12
15. Let f(x) = –6x2 + 3x – 10 and g(x) = –12x + 4. Find (f – g)(x).
16. Let f(x) = x + 1 and g(x) = –x2 – x + 1. Find (f • g)(x).
17. Let f(x) = 5x + 6 and g(x) = 8x + 6. Find (f • g)(x).
A) 13x2 + 25x + 12
B) 40x2 + 78x + 36
C) 40x2 + 78x + 36
D) 40x2 + 14x + 36
18. Let f(x) = 3 and g(x) = 5x + 3. Find (f g)(x).
21. Use the following tables to evaluate (g ? f)(1).
x f(x) x g(x)
–3 3 –3 –3
–1 –3 0 2
1 6 3 0
3 0 6 –1
22. Let f(x) = –x – 2 and g(x) = –x2 + 1. Find
A) –3
B) 0
C) –2
D) 1
25. The total cost in hundreds of dollars of producing x items per hour in an 8-hour shift is given by the function C(x) = 14x. Suppose that the number of items produced per hour for an 8-hour period is a function of the time t after an 8-hour shift begins and is given by x(t) = –t2 + 7t + 8, . Write a function f(t) to represent the hourly cost in hundreds of dollars at time t.