(5) Consider the function f(x, y, z) = 12 + 2y? + 422 - 1. If we set f(x, y, z) equal to a constant we obtain a level surface. (a) Describe the level surface f(r, y, z) = 3. What kind of surface is this? (Elliptic parabo- loid, hyperbolic paraboloid, ellipsoid, etc.) (b) Compute the gradient of f and evaluate it at the points P(2, 0, 0), Q(0, v2, 0), R(0, 0, 1), S(1, 1, 1/2), all of which are on the level surface.(c) In each case, the gradient points in the direction that f has the maximum rate of increase. Are these gradient vectors pointing out of the solid f(x, y, z)