Let be the nth derivative
Then find the value of , if
This is a second order homogeneous differential equation. You can solve it using the methods explained under the heading "Second Order Differential Equations" on this guide: http://www.mathhelpforum.com/math-he...-tutorial.html
In particular you need to find the characteristic equation and solve its roots.
Have you made any progress on this problem? What exactly are you stuck on?