vector identity

[Kolahal Bhattacharya]

1. The problem statement, all variables and given/known data

I am to show: closed integral {phi (grad phi)} X (n^)dS=0

2. Relevant equations



3. The attempt at a solution

I understand I am to use divergence theorem here.but cannot approach.Please help

[Dick]

Is 'X' supposed to mean a cross product between the normal vector and the gradient?

[Kolahal Bhattacharya]

yes.It means that.

[Dick]

Try using \int_S n \times a dS = \int_V curl(a) dV.