Suppose f(x, y)=xyf(x, y)=xy, P=(−4,4)P=(−4,4) and v=−2i−1jv=−2i−1j. A. Find the gradient of f. ∇f=∇f= i+i+ jj Note: Your answers should be expressions of x and y; e. g. "3x - 4y" B. Find the gradient of f at the point P. (∇f)(P)=(∇f)(P)= i+i+ jj Note: Your answers should be numbers C. Find the directional derivative of f at P in the direction of vv. Duf=Duf= Note: Your answer should be a number D. Find the maximum rate of change of f at P. Note: Your answer should be a number E. Find the (unit) direction vector in which the maximum rate of change occurs at P. u=u= i+i+ jj Note: Your answers should be numbers