So I am trying to follow my professors notes. Here is my work on the proof. And on the bottom is my answer and his answer. I know my answer is wrong, as I do not fully understand how to convert the summations at the end to their vector quantities. Is my work incorrect? [PLAIN]http://img256.imageshack.us/img256/6175/questionn.gif [Broken] I do not even know what F times nabla means. I know nabla times F is divergence. Are they the same???? EDIT: Oh and his G is my q. AND his answer has a -(G*Nabla)*F at the end.