# Infinite series solution for NON-linear ODEs?

1. Sep 11, 2008

### smallphi

infinite series solution for NON-linear ODEs???

Is it possible to use the infinite series method (Frobenius) to obtain general solutions of non-linear ODE's, I wanna try a second order equation. Any good references where I can see how that goes exactly?

2. Sep 11, 2008

### HallsofIvy

Re: infinite series solution for NON-linear ODEs???

No. Frobenius' method and series methods in general assume that you can "add" solutions. That is only true for linear differential equations.

3. Sep 11, 2008

### smallphi

Re: infinite series solution for NON-linear ODEs???

The solution of a non-linear ODE is a function that can be expanded in power series and I've actually seen non-linear ODE's solved that way. The question is wether there is a book/article that focuses specifically on such type of solving cause I don't want to spend months reinventing the wheel and the hot water?

4. Sep 11, 2008

### matematikawan

Re: infinite series solution for NON-linear ODEs???

May be for first order DE it is possible to use power series method because of the existence and uniqueness theorem.

For higher order, if you are still interested in series solution, try the Adomian method. I understand that it is an iterative method but the series obtained converges quickly (please forgive me if I'm wrong. I only saw it in seminars. Hopefully I will be able to learn properly this method one day)