Find the directional derivative of the function at the given point in the direction of the vector v. f(x, y, z)=xyz, (2, 1, 8), V = (-1, -2, 2) Duf(2, 1, 8) = [-/5 Points] DETAILS Find the directional derivative of f(x, y, z) = xy + yz + zx at P(1, -1, 2) in the direction from P to Q(2, 4, 5). Duf(1,-1, 2) = [-/5 Points] DETAILS SCALC7 14.6.020. maximum rate of change direction vector Find the maximum rate of change of f at the given point and the direction in which it occurs. f(x, y, z) = 3x + 4y, (5, 4, -1) Z SCALC7 14.6.024.