1. For the cone z = vx2+ y2, sketch the cone and also the contours and level curves for c = 0, 1, 2, 3. (Make sure you first find and write down the equations of the level curves and recognize what curves they represent. ) 2. For f(x, y) = xy and c = -9, -4, -1, 0, 1, 4,9, find and sketch the level curves f (x, y) = c. (Make sure you first find and write down the equations of the level curves and recognize what curves they represent.)