Suppose f(x,y) = x/y, P = (-1,2) and v = -4i + 4j.
A. Find the gradient of f.
i+
j
Note: Your answers should be expressions of x and y; e.g. "3x - 4y"
B. Find the gradient of f at the point P.
(Vf)(P) = i+
j
Note: Your answers should be numbers
C. Find the directional derivative of f at P in the direction of v.
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 = i+
j
Note: Your answers should be numbers