## Calculus (3rd Edition)

$V' = 3\pi r^2$
First, we look at the equation for the volume of a cylinder: $V = \pi r^2 h$ We are given that the height is equal to the radius, so we can simply the formula to be: $V = \pi r^3$ Now, for the rate of change, we need to find the derivative of the function with respect to the radius: $V' = 3\pi r^2$