For # 6-9, write an iterated triple integral in the indicated coordinate system for the integral of f (x, y, z) = 2 - 8x over the region D in the first octant bounded by the cone z = (/x2 + y2 , the cylinder x2 + y? = 1, and the coordinate planes. 6) Cartesian (rectangular) coordinates (dz dy dx) 7) Cylindrical coordinates (dz dr de) 8) Spherical coordinates (do do de) 9) Find the integral of f by evaluating one of the triple integrals (the easiest. of course)