Precalculus Examples

$f (x) = {\begin{cases} {(x + 8)}^{2} - 5 & x \neq - 5 \\ - 1 & x = - 5 \end{cases}$ Find $f (- 5)$

Step 1

Identify the piece that describes the function at $x = - 5$ . In this case, $x = - 5$ falls within the interval $x = - 5$ , therefore use $- 1$ to evaluate $f (- 5)$ .

$f (x) = {\begin{cases} {(x + 8)}^{2} - 5 & x \neq - 5 \\ - 1 & x = - 5 \end{cases}$

Step 2

The function is equal to $- 1$ at $x = - 5$ .

$f (x) = - 1 (]_{x = - 5}^{})$

Step 3

Evaluate the function at $x = - 5$ .

$f (- 5) = - 1$