2z (10) 21. Use the Divergence theorem to find the outward flux of F = In (x2 + y2)i - tan X + z x2 +y2 k across the boundary of the region D which is the thick - walled cylinder 1 s x2 + y2 s 2, - 1 Sz S2. (10) 22. Use the Divergence theorem to find the outward flux of F = (y - xi + (z-yi + (y - x)k across the boundary of D which is the cube bounded by the planes x = + 1,y =+ 1, and Z=+1