Consider the function f(x,y) = 6- a. Find the value of the directional 2 21 2 3 -y2, whose graph is a paraboloid (see figure). derivative at the point (1,1) in the direction b. Sketch the level curve through the given point and indicate the direction of the directional derivative from part (a). a. The directional derivative is (Type an exact answer, using radicals as needed.)