Partial derivatives?? Volume of a hollow cone.

V = pi*r*sqrt(r^2+h^2)
the partial derivative for r and h?

Since V = πr (r^2 + h^2)^(1/2),

Holding h constant,
∂V/∂r = π * 1 * (r^2 + h^2)^(1/2) + πr * (1/2) (r^2 + h^2)^(-1/2) * (2r)
........= π(r^2 + h^2)^(1/2) + πr^2 (r^2 + h^2)^(-1/2).

Holding r constant,
∂V/∂h = πr * (1/2) (r^2 + h^2)^(-1/2) * (2h)
........= πrh (r^2 + h^2)^(-1/2).

I hope this helps!