Question: how to find the slope of z?
Answer: 1 Answers. #1. +5. The general equation for a sphere, centred at (0,0,0) is x2 + y2 + z2 = r2 Rearrange this as z = (r2 - x2 - y2)1/2 The slope of z with respect to x is given by. ∂z/∂x = -x/ (r2 - x2 - y2)1/2 The slope of z with respect to y is given by. ∂z/∂y = -y/ (r2 - x2 - y2)1/2 ...  11 Online Users.