Take the derivative of the formula for the surface area of a sphere and plug 3 in for r once you've taken the derivative.
Post if you need more clarification.
What is the rate of change of the area of a sphere with respect to the radius when the radius is r=3?
I have a vague idea.
They want us to use (f(t+h)-f(t))/h.
Guess: Plug in t as as t ans solve. Then plug 2 in for r.
Thanks!