(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I just have a problem with series solutions when I get to the point of needing to find the recursion relation........and a few other problems.

2. Relevant equations

Assume y can be written ∑a_{n}x^{n}

3. The attempt at a solution

So, on y'' + xy' + 2y = 0, I got to the point of

a_{n+2}=-a_{n}/(n+1). I wrote out a few n's but still can't figure outexactlywhat the relation is. A little help, maybe?

On another problem, (1+x2)y'' - 4xy' + 6y = 0, I got the point of

2a_{2}+ 6a_{3}x - 4a_{1}x + 6a_{0}+ 6a_{1}x + [n=2 to ∞]∑( (n+1)(n+2)a_{n+2}+ (n-1)na_{n}- 4na_{n}+ 6an)x^{n}= 0.

Now what? Detailed help would bemuchappreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Finding a recursion relation

**Physics Forums | Science Articles, Homework Help, Discussion**