Vector Identity proof

1. Dec 8, 2005

QuantumDefect

Hello, I need some help on this vector identity. Im supposed to prove that Del Dot (Del(g(r)))=(2/r){dg(r)/dr}+(d^2g(r)/dr^2). Using Cartesian Coordinates. Any help would be GREATLY appreciated> :)

2. Dec 8, 2005

robphy

How is r related to your Cartesian coordinates?
Do you know the chain rule?

3. Dec 8, 2005

QuantumDefect

r^2=x^2+.....?

I think thats what I have to do! I was using r=x*x_hat+.... Ill try that, thanks!