Basic Operations

Basic Operations

Evaluating Functions

Example 2

Given g(x) = x2 – 4, find g(3).

Step 1. Eliminate the input value “x” and replace it with parentheses.

g ( ) = ( )2 – 4

Step 2. Place the input value of 3 inside the parentheses.

g (3) = (3)2 – 4

Step 3. Simplify the right side of the equation.

g (3) = 9 – 4

g (3) = 5

*Note: This is read, “The function g, with an input of 3, has an output of 5.
This can be graphed as the ordered pair (3, 5).