a) Find the outward flux of the vector field F (x, y,z) = x'i+ yj + (z3 + xz)k across the surface of the region that is enclosed by the hemisphere z = Ja? - x y? and the plane z = 0. %3D b) Use the transformation u = 2x y, v =x+3y to find fR (2x-y) dA, x+3y where R is the rectangular region enclosed by the lines 2x-y 0, 2x - y 1, x+3y 1, x + 3y = 3.