Consider the function f(x,y) = 5 - 5 y , whose graph is a paraboloid (see figure). 12 V2 a. Find the value of the directional derivative at the point (1,1) in the direction 2 2 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.)