# Quick Simple homogenous equation help

• May 4th 2010, 11:51 AM
signature
Quick Simple homogenous equation help
If i have the function:

$\frac{d^2u}{dx^2} + 4u = f(x)$

What would the homogenous equation be?
• May 4th 2010, 05:04 PM
dwsmith
Quote:

Originally Posted by signature
If i have the function:

$\frac{d^2u}{dx^2} + 4u = f(x)$

What would the homogenous equation be?

$\frac{d^2u}{dx^2} + 4u = 0$
• May 6th 2010, 08:35 PM
matheagle
so $U(x)=a\sin(2x)+b\cos(2x)$ for all a,b.