# Maximum and minimum

by minia2353
Tags: maximum, minimum
 Math Emeritus Sci Advisor Thanks PF Gold P: 39,345 Looks pretty direct to me. If $f(x_0)$ is a maximum for f, then $f(y)\le f(x_0)$ for all y.Since square root is an increasing function, $\sqrt{f(y)}\le \sqrt{f(x_0)}$.