Evaluate the Function f(4) = square root of 4

$f (4) = \sqrt{4}$

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

$f (4) = \sqrt{4}$

Simplify the result.

Remove parentheses.

$f (4) = \sqrt{4}$

Rewrite $4$ as $2^{2}$ .

$f (4) = \sqrt{2^{2}}$

Pull terms out from under the radical, assuming positive real numbers.

$f (4) = 2$

The final answer is $2$ .

$2$