Please answer with work

(1 point) Suppose that f(x, y, z) - x yz - zyz is a function of three variables 1. Find the gradient of f (2, y, =). Answer V f(z, y, 2) - 2. Evaluate the gradient at the point P( 1, 2, -1). Answer. V f (-1, 2, -1) 3. Find the rate of change of f (c, y, z) at P in the direction of the vector u = (0, =, - Answer. Du f(-1, 2, 1) =