Precalculus Examples

$f (x) = {\begin{cases} - x + 2 & x < 1 \\ 2 & x = 1 \\ 6 & x > 1 \end{cases}$ Find $f (4)$

Step 1

Identify the piece that describes the function at $x = 4$ . In this case, $x = 4$ falls within the interval $x > 1$ , therefore use $6$ to evaluate $f (4)$ .

$f (x) = {\begin{cases} - x + 2 & x < 1 \\ 2 & x = 1 \\ 6 & x > 1 \end{cases}$

Step 2

The function is equal to $6$ at $x = 4$ .

$f (x) = 6 (]_{x = 4}^{})$

Step 3

Evaluate the function at $x = 4$ .

$f (4) = 6$