Precalculus Examples

$f (x) = {\begin{cases} - x - 9 & x \neq - 4 \\ - 4 & x = - 4 \end{cases}$ Find $f (- 4)$

Step 1

Identify the piece that describes the function at $x = - 4$ . In this case, $x = - 4$ falls within the interval $x = - 4$ , therefore use $- 4$ to evaluate $f (- 4)$ .

$f (x) = {\begin{cases} - x - 9 & x \neq - 4 \\ - 4 & x = - 4 \end{cases}$

Step 2

The function is equal to $- 4$ at $x = - 4$ .

$f (x) = - 4 (]_{x = - 4}^{})$

Step 3

Evaluate the function at $x = - 4$ .

$f (- 4) = - 4$