I am learning Calc III and am up to the section about gradients and directional derivatives. I was given a word problem involving a person on a mountain who measures a 4-degree rise due west and a 3-degree rise due north. I know that when facing east the slope of a terrain is given by \(\frac{\partial f}{\partial }\) and when facing north the slope of a terrain is given by \(\frac{\partial f}{\partial y}\) but what is the slope when facing west? Is it \(\frac{\partial f}{\partial z}\)?