1. The problem statement, all variables and given/known data 2. Relevant equations The double integral at S of the (curl of)F.n. 3. The attempt at a solution We find the the normal vector to the surface S is (2/7, 6/7, -3/7), right or not? We compute the curl of F which is -2y, right? Then, we calculate the dot product and we get 6y/7. Am I doing it right? If so, can someone tell me what to do next, and if not, can someone tell me how to properly solve it. I'm fairly new to the concept so please be patient with me.