Ashley P.

# Vector Differentiation

Prove that (grad)^2 f(r) = D^2/dr^2 + (2/r) Df/Dr

Where D^2/dr^2 refers to the second partial derivative of f , w.r.t. r and

Df/ Dr refers to partial derivative of f, w.r.t r

vector r = xi + yj + zk and f(r) is twice differentiable