# How do you evaluate the function  f(x)= -x^2 + 5 for f (4)?

Mar 4, 2018

See a solution process below:

#### Explanation:

For each occurrence of $\textcolor{red}{x}$ in $f \left(x\right)$ substitute $\textcolor{red}{4}$ and calculate the result:

$f \left(\textcolor{red}{x}\right) = - {\textcolor{red}{x}}^{2} + 5$ becomes:

$f \left(\textcolor{red}{4}\right) = - {\textcolor{red}{4}}^{2} + 5$

$f \left(\textcolor{red}{4}\right) = - 16 + 5$

$f \left(\textcolor{red}{4}\right) = - 11$