1. The problem statement, all variables and given/known data I just want to know how to get from this: ∂ø^/∂ø = -x^cosø - y^sinø to this: = -(r^sinθ+θ^cosθ) 2. Relevant equations All the equations found here in the Spherical Coordinates section: http://en.wikipedia.org/wiki/Unit_vector 3. The attempt at a solution I've tried a bunch of ways of algebraically getting the answer but I seem to be getting nowhere. Maybe I'm missing an equation. I tried adding and subtracting z^cosθ to get -r^ but I'm still missing the other piece. Please help! Thanks so much.