# Inhomogeneous PDE

• February 6th 2011, 11:56 PM
bnay
Inhomogeneous PDE
Hello everybody,

I'm having trouble figuring out where to go with this PDE. We've done equations that can be reduced to have homogeneous boundary conditions, but we haven't covered much where they can't (or at least not in the way I've tried). In the question below I tried the method I've learned so far, letting u(x,t) = X(x)T(t), but that got me nowhere because the factor of gamma*u threw things off a bit.

Anyways, my question is: What should I substitute for u(x,t) so that I can use separation of variables? I'm just looking for a starting point for this question, and then I should be able to take it from there.

Thank you very much for your help

http://img195.imageshack.us/img195/86/ee323assn3q4.png
• February 7th 2011, 05:23 AM
Jester
Separation of variables still works (provided that $\gamma$ is a constant). You can also transform the $\gamma u$ term away under the transformation

$u(x,t) = e^{-\gamma t} v(x,t)$.
• February 7th 2011, 05:25 AM
bnay
Quote:

Originally Posted by Danny
Separation of variables still works (provided that $\gamma$ is a constant). You can also transform the $\gamma u$ term away under the transformation

$u(x,t) = e^{-\gamma t} v(x,t)$.

Thank you very much. I'll try that