not necessarily. the radius is given, but get rid of it. solve for r in terms of h (similar triangles is usually the best way to do this) then replace r in the formula with the function of h so you have the volume as a function of the height only, then differentiate implicitly, the only unknown will be dh/dt, solve for it.Question 2: if you start with V=(1/3)pi*r^2h does that mean that r (radius) and h (height) are already given?
dV/dt is given. read the question again, it is 80 ft^3/minQuestion 3: if i'm solving for dh/dt then what/how do i find what dV/dt is to begin with