The usual form of Legendre's differential equation which I am familiar with, is: $$ \left(1-x^2\right)\frac{\mathrm d^2P}{\mathrm dx^2} - 2x\frac{\mathrm dP}{\mathrm dx} + \ell\left(\ell+1\right)P = 0 \tag{01} $$
No problem, use series solution to solve.
But when I was looking at the solution of Schrodinger's equation for Hydrogen atom, the equation they got was this: $$ \left(1-x^2\right)\frac{\mathrm d^2P}{\mathrm dx^2} - 2x\frac{\mathrm dP}{\mathrm dx} + \left[\ell\left(\ell+1\right)- \frac{m^2}{1-x^2}\right]P = 0 \tag{02} $$
Awesome! Now how on earth do I solve this? with the extra $\frac{m^2}{1-x^2}$ term?
I guess I could multiply by that on both sides and get rid of it from the denominator but then is it still Legendre equation? Have I read something wrong?
Thank you for your help and as always apologies if I missed something obvious and the question is silly!
ANSWER: Here's the link to a step by step solution for the general Legendre equation: http://www.physicspages.com/2011/03/22/associated-legendre-functions/