Thanks. Been a lurker for years on several sites, decided it is probably time to join up for my own questions.
I'd say the first part of S, 2*pi*r*h, is just V'. I guess I could say 2*pi*r^2 is equivalent to 2*(V/h). So at that point just take the partial w/respect to V?
From the two equations given below, find ∂s/∂V (holding h constant) and ∂h/∂V (holding r constant
V = π*r^2*h, S = 2π*r*h + 2*π*r^2
Not entirely sure where to start...