## Calculus (3rd Edition)

The minimum value is $f(2)=-128$ and the maximum value is $f(-2)=128$
$f'(z)=5z^{4}-80$ is differentiable everywhere. The critical points of the function are the solutions of $5z^{4}-80=0$. $5z^{4}-80=0$ when $z=2$ or when $z=-2$. The critical points of $y$ are 2 and -2. We compare the values of the function at the critical points and the end points to obtain the maximum and minimum value. $f(2)=(2)^{5}-80(2)=-128$ $f(-2)=(-2)^{5}-80(-2)=128$ $f(3)=(3)^{5}-80(3)=3$ $f(-3)=(-3)^{5}-80(-3)=-3$ The minimum value is $f(2)=-128$ and the maximum value is $f(-2)=128$