Prove the divergence theorem for the vector field A = p = (x,y) and taking the volume V to be the cylinder of radius a with its base centred at the origin, its axis
parallel to the z-direction and having height h.
I can find the dV side of the equation fine (I think) however am unable to do the dS side to show they are equal to each other
∫∫∫div(A) dV = ∫∫ (A . n) dS
The Attempt at a Solution
∫∫∫div(A) dV = 2*∏*r^2*h
∫∫ (A . n) dS = ???????
Many thanks for all hints and help