1. The problem statement, all variables and given/known data So trying to find the Integral of A.n dS where A is (y,2x,-z) and S is the surface of the plane 2x+y = 6 in the first octant cut off by the plane z=4 2. Relevant equations 3. The attempt at a solution So i always solve these by projection...but im a bit confused this time.. normally the surface is in the form z=f(x,y) so i do z-f(x,y) and take grad to find the normal.. so is the normal vector here just (2,1)? ie. grad 2x-y-6 = 0? In which case is the integral just the double integral of (y,2x,-4).(2,1,0) dA? Im a bit confused..Any help would be great!