Use the data tables for f(x) and g(x) above to answer questions 6 and 7 below.

Question

X         -2         0         1         5         8         11         15

f(x)       2         3         7         10       8         4           1

X         -3         1         3         6         7        10          11

g(x)     0          2         5         3        8         4             1

6.  What is the value of f(g(3)?   

1.  5              b.    6              c.  10              d. This is undefined

7.  For which value of x would the composition g (f(x)) be undefined?

1.  - 2              b. 0                c. 1               d.  5                 e. 15

Answer 1

f[g(3)] = f(5) because g(3) = 5 based on the table.

Then f(5) = 10. (Choice C)

g[f(-2)] = g(2) = undefined

g[f(0)] = g(3) = 5

g[f(1)] = g(7) = 8

g[f(5)] = g(10) = 4

g[f(15)] = g(1) = 2

g[f(x)] will be undefined if x = -2.