Vaxima Taylor expansion of Diff.Eq.

[Linc Madison]

I am trying to use Vaxima to do a Taylor expansion of a nonlinear
2nd order differential equation.  What I have is an equation of
the form

   x" + kx + epsilon{cx' + dx'|x'| + e x'^3 + f sign(x') } = 0 .

The terms in brackets replace the usual cx' term to represent
nonlinear damping of an oscillatory system.  I need to get an
expanded solution of this equation to about third order in epsilon,
and it seems like I should be able to use Vaxima to help.

The problem is, I am a rank novice with Vaxima, and am finding it
very slow going learning how to talk with it.  I've used the
function ODE2 successfully on the linearized equation, but I
haven't figured out how to connect TAYLOR with ODE2 (all I've gotten
so far is the enormously helpful result that the Taylor expansion of
" x " is " x + ... ").

Can anyone out there in netland tell me the proper way to go about
vaximizing this problem?  Also, if I'm hopelessly hitting the wrong
audience in comp.unix.questions, please refer me to the right group.

Minnie thangks,
-- Linc Madison  =  rmadison at euler.berkeley.edu
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