Adding & Subtracting
Evaluating
Functions can also be added or subtracted given a domain value. First evaluate each function for the given domain then perform the indicated operation using the output values.
Example If f(x) = 2x2 and g(x) = 3x2 + 1, what is f(2) + g(3) ?
Step 1. Evaluate each function
f(2) = 2(2)2 = 8
g(3) = 3(3)2 + 1 = 28
Step 2. Add the output values of the two functions
f (2) + g(3)
= 8 + 28
= 36