y'''+y''+y'+y=x^2

thanks

Printable View

- Dec 28th 2010, 07:45 PMceodesolve
y'''+y''+y'+y=x^2

thanks - Dec 28th 2010, 11:52 PMFernandoRevilla
The roots of the characteristic equation are $\displaystyle -1,\pm i$, so the general solution for the homogeneus is:

$\displaystyle y_h(x)=C_1e^{-x}+C_2\cos x+C_3\sin x$

A particular solution for the complete has the form :

$\displaystyle y_p(x)=Ax^2+Bx+C$

Try it.

Fernando Revilla