# Homework Help: Differential equations and series

1. Dec 2, 2013

### freshman2013

1.

1.The problem statement, all variables and given/known data

Use power series to evaluate intial value problem y''-xy'-2y=4x^2 y(0)=1 and y'(0)=1

2. Relevant equations

3. The attempt at a solution

I got the series Cnx^n and took its derivative and plugged it into the formula and I got but when I factor out x^n and set that experssion equal to 4x^2, I realize I'm stuck and I'm not sure If I'm doing it correctly.

Last edited: Dec 2, 2013
2. Dec 2, 2013

### pasmith

What that tells you is that coefficient of $x^2$ on the left hand side is 4, and the coefficient of every other power of $x$ on the left hand side is zero.