## College Algebra 7th Edition

$r = \sqrt{\dfrac{3V}{\pi{h}}}$
Multiply $3$ to both sides to obtain: $3V=\pi{r^2h}$ Divide $\pi{h}$ to both sides to obtain: $\dfrac{3V}{\pi{h}}=r^2$ Take the square root of both sides to obtain: $\pm\sqrt{\dfrac{3V}{\pi{h}}}=r$ The $r$ in this formula/equation is radius. A radius is a length therefore it cannot be negative. Thus, $r = \sqrt{\dfrac{3V}{\pi{h}}}$