1. The problem statement, all variables and given/known data I'm given an equation describing a string on an elastic foundation: utt+w20u = c2uxx with the boundary conditions u(0,t)=u(l,t)=0. 3. The attempt at a solution I think I understand how to do this problem up to a certain point, but that point occurs when I find the actual eigenfrequencies. I'm not exactly sure what they are, in a general meaning, however I have attached my solution nonetheless. http://img695.imageshack.us/img695/628/scan2j.jpg" [Broken] Thank you for your help.