7.
9.
11.
13. Use the symmetry and homogeneity of the region to look only at the
front left half (viewed from the usual perspective) and double that, producing .
15. It's an ugly problem, but if forced to do it here's what I'd do:
First pull a trick, and interchange the x and z axes, so we're finding
the integral of the function z for the region E bounded by z = 4x2
+ 4y2 and the plane z = 4. Yes, you can do that. Then the integral
sets up most easily in polar (or cylindrical, to be proper) coordinates
as .
17. It's a tetrahedron with intercepts (6,0,0), (0,4,0), and (0,0,2).
The most natural integral is .
19. .