I want to solve the Van der Pol equation:
$$f''+ \mu \, (f^2-1)f'+f=0, \quad f = f(t),$$
by Padé approximation.
I know the solution should be the combination of $\sin{t}$ and multiplied by $\mu$, then I apply Padé approximation equating to a fraction with $2$ power series and find $p$ and $q$.
However, I just do not how to work out my original $f$.
Thank you very much for your help