# A Solve DE for theta component (hydrogen WF)

1. Jan 8, 2017

### Andrew Deleonardis

The particular equation I would like to see solve is:
$\sin\theta\frac{d}{d\theta}(\sin\theta\frac{d\Theta}{d\theta})+\Theta(l(l+1)\sin\theta-m^2)$

The solution for this equation is the following associated laguerre polynomial:
$P^m_l(\cos\theta)=(-1)^m(\sin\theta)^m\frac{d^m}{d\cos\theta^m}\bigg(\frac{1}{2^ll!}\frac{d^l}{d\cos\theta^l}(cos^2\theta-1)^l\bigg)$

This equation is involved in solving the schrodinger equation for the hydrogen atom.
Even though I already know the answer, I would like to know HOW to solve it

2. Jan 8, 2017

### blue_leaf77

Although never tried it myself, associated Legendre differential equation can be solved by power series expansion. For the ordinary Legendre differential equation see this. I guess you should be able to get the idea from that link when applied to the associated Legendre equation.
By the way, no one can solve the equation you have there until you add equal sign and some terms in the other side.

Last edited: Jan 8, 2017
3. Jan 9, 2017

### Andrew Deleonardis

Oh oops, it's meant to equal zero, I forgot

4. Jan 9, 2017