a For the function f(x), substitute - 2 for x in each instance of the x-variable.
B
b For the function g(x), substitute - 1 for x in each instance of the x-variable.
C
c For the function g(x), substitute 4 for x in each instance of the x-variable.
D
d Substitute - 7 for x in the function f(x) and 1 for x in the function g(x).
E
e Substitute 3 for x in the function f(x) and 2 for x in the function g(x).
A
a Undefined, see solution.
B
b - 27
C
c 8
D
d 0
E
e - 1
Practice makes perfect
a Using the function f(x), we want to evaluate for the given value f( - 2). To do this we need to substitute - 2 for x in each instance of the x-variable.
Oops! Dividing by zero is impossible! As we can see, evaluating the function at - 2 results in a zero in the denominator. Therefore, the function is undefined at x=- 2.
b Using the function g(x), we want to evaluate for the given value g( - 1). To do this we need to substitute - 1 for x in each instance of the x-variable.
d Using the given functions f(x) and g(x), we want to evaluate for the given value f( - 7)+g( 1). To do this we need to substitute - 7 for x in the function f(x) and 1 for x in the function g(x) and evaluate the sum.
e Using the given functions f(x) and g(x), we want to evaluate for the given value f( 3)+g( 2). To do this we need to substitute 3 for x in the function f(x) and 2 for x in the function g(x) and evaluate the difference.
