# Inhomogeneous wave equation help

1. Nov 9, 2009

### finmath

I need help solving 3Utt+10Uxt+3Uxx=sin(x+t)

I have found the homogeneous part, which is U(x,t)=f(3x-t) +g(x-3t), but I don't know where to go from there. Any help would be much appreciated!

2. Nov 9, 2009

### arildno

Well, make a trial solution $$U_{p}(x,t)=A\sin(x+t)$$ and see if you can determine what "A" must be.

3. Nov 9, 2009

### finmath

Back to the basics! For some reason I thought it was going to be way more difficult.
My final solution is U(x,t)=f(3x-t) + g(x-3t) - sin(x+t)/16

4. Nov 11, 2009

### matematikawan

I though the try function should be of the form

$$U_{p}(x,t)=A\sin(x+t) + B\cos(x+t)$$

5. Nov 11, 2009

### arildno

And B will be 0..