Evaluating a function involves replacing the variable, such as x, with a value from the function's domain and computing the result. This is denoted as f(x), where x is substituted into the function f. For example, if evaluating f(x) = x^2 when x = 3, it is computed as f(3) = 9. Similarly, if evaluating g(x) = x + 5 when x = -2, it is computed as g(-2) = -2 + 5 = 3.

1. EVALUATING A FUNCTION…
 In evaluating a function means replacing
the variable in the function, in this case the x-
value, with a value from the function domain
and computing for the result.
 To denote that we are evaluating “f” and
“x” for some “x” in the domain of “f”, we
write ( )
Example: Evaluate the functions below if
.
(1) ( )
Solution:
( )
( ) ( )
( )
( )

2. (2) ( )
Solution:
( ) ( )
( )
( )
( )