How to solve this differential equation?

1. Dec 21, 2005

wormhole

how can i solve this differential equation?

$${(\frac{d^2y}{dx^2})}^2+ay(x)+b=0$$

2. Dec 21, 2005

Tide

HINT: Define a new variable $z(x) = y(x) + b/a$

3. Dec 21, 2005

wormhole

ok i figured it out
any polinom of degree two will do it
thanks