# Stupid simplification question

1. Oct 19, 2011

### CyberShot

http://imageshack.us/photo/my-images/809/equationu.png/

I'm not understand this simple step.

Btw, this isn't technically a homework question so I think it should be fine posting it here.

Thanks

2. Oct 19, 2011

### Char. Limit

Let $u=\alpha^2$ and then solve for u via the quadratic formula. It'll come out plain as day.