Precalculus Examples

$f (x) = x^{2} - 2 x$ , $f (4)$

Step 1

Replace the variable $x$ with $4$ in the expression.

$f (4) = {(4)}^{2} - 2 \cdot 4$

Step 2

Simplify ${(4)}^{2} - 2 \cdot 4$ .

Tap for more steps...

Step 2.1

Remove parentheses.

${(4)}^{2} - 2 \cdot 4$

Step 2.2

Simplify each term.

Tap for more steps...

Step 2.2.1

Raise $4$ to the power of $2$ .

$16 - 2 \cdot 4$

Step 2.2.2

Multiply $- 2$ by $4$ .

$16 - 8$

Step 2.3

Subtract $8$ from $16$ .

$8$