Find the directional derivative of φ = x^2yz + 4xz + xyz at (1,2,3) in the direction of vector(2i + j − k).

Question

Directional derivative = ∇φ. vector (a/|a|)

Find the directional derivative of φ = x2yz + 4xz + xyz at (1,2,3) in the direction of vector(2i + j − k).

Answer 1

Given: = x2yz + 4xz2 + xyz