Thanks for your reply. However that is something I already considered. For the case where u=1 and I have terms (u-1)^n I simply expanded that into a polynomial of degree n in u. I then grouped all of the u^n terms together for my final polynomial. Here are the equations and results I have...
Homework Statement
As per Griffiths 3.21, I am given the on axis potential a distance r from a uniformly charged disk of radius R as a function of \sigma. Using this and the general solution for laplace's equation in spherical coordinates with azimuthal symmetry, calculate the first three...