5. Determine the centroid of the solid generated by revolving the area bounded by the curve y = x2, y = 9, and x = 0, about the y - axis. 6. Determine the centroid, C(x, y, z), of the solid formed in the first octant bounded by y = 4 - x2 and x - z = 0. 7. What is the volume in the first octant bounded by x2 = 16 - y and z+ y= 16. 8. Determine the centroid, C(x, y, z), of the solid formed in the first octant bounded by z + y - 16 = 0 and 2x2 - 2(16 - y) = 0