# Finding the particular solution of DE

1. Mar 18, 2006

### overseastar

I have a nonhomogeneous DE and wants to find the particular solution for Asin(x)sin(t)

Is there any tips in using method of undetermined coefficient to guess the particular solution of this?

2. Mar 19, 2006

### HallsofIvy

Is this a partial differential equation or is one of x and t the dependent variable so that you have a nonlinear equation? In either case "undetermined coefficients" doesn't apply here.

3. Mar 19, 2006

### overseastar

the question is asking us to solve this nonhomogeneous problem:

Utt = Uxx + sin(x)sint(t)

and I think in one step of the calculations, we need to find the general solution of sin(x)sin(t) along with the particular solution.

Or is there another way to approach this question?

4. Mar 19, 2006

### masudr

Stipulate that U(x,t)=X(x)T(t). Then you can separate into 2 ODEs.

5. Mar 19, 2006

### overseastar

Sorry, I guess I should be more specified.
It asked us to use the Fourier Series Method.