Separation of Variables Spherical Coordinates

[cooev769]

Homework Statement

So I'm doing a question from one of my past exams as attached, there are no copy right issues with this document that I know of and have asked my lecturer who wrote the exam and he said I am welcome to upload it. The question is 1)b)iv), my attempt is attached. I end up with a 2l+1 where there should just be 1, can anybody tell me where I went wrong?

Homework Equations

Relevant equations are attached in the past exam

The Attempt at a Solution

My scan is too large to attach so please use the url provided. Thanks

http://tinypic.com/r/4ki9w5/8

 

[cooev769]

Solved I was adding the two instead of subtracting them. I can do electrodynamics but I can't do simple addition. Time to go and cuff my primary school teacher.