# Variation of parameters- 2nd order linear equation

1. Dec 9, 2013

### hahaha158

1. The problem statement, all variables and given/known data
solve 4y''-4y'+y=16et/2

2. Relevant equations

v1= -∫ y2g/w
v2= ∫ y1g/w

3. The attempt at a solution

http://imgur.com/gxXlfdH

the correct answer is 2t^2 e^(t/2) instead of what i have though, i am not sure what i am doing wrong?

2. Dec 9, 2013

### pasmith

You need to divide by the coefficient of $y''$ before you start:
$$y'' - y' + \frac14 y = 4e^{t/2} \equiv g(t).$$