Let f(x,y,z) = .Find the directional derivative of f(x,y,z) at the point (1,3,-2) in the direction of the vector [3,-1,4]

Answer 1

So what is the function ?
by the way search for:
calculator-online.net/directional-derivative-calculator/

Answer 2

well, you know it's ∇f•[3,-1,4]
so plug and chug.