1. The problem statement, all variables and given/known data 2. Relevant equations Definitely related to the divergence theorem (we're working on it): 3. The attempt at a solution I'm a bit confused about multiplying a scalar field f into those integrals on the RHS, and I'm not sure if they can be taken out or not. If they can be, I evaluated the RHS out to be 0 (zero), which doesn't make sense with my evaluation of the LHS, which is just grad f dotted into F. On the other hand, if it CAN'T be taken out of the integral, I'm at a loss as of how this relates to the divergence theorem.. I'm not sure what I'm missing here :( Help would be very much appreciated!