Re: Solving a nasty rational differential equation
- To: mathgroup at smc.vnet.net
- Subject: [mg74625] Re: Solving a nasty rational differential equation
- From: dh <dh at metrohm.ch>
- Date: Thu, 29 Mar 2007 02:25:57 -0500 (EST)
- References: <eud32p$k50$1@smc.vnet.net>
$Version=5.1 for Microsoft Windows (October 25, 2004)
Ho Roger,
if you want a clear cut answer, then do not give details that are
irrelevant and can not be understood without context , but concentrate
on the question. I can only guess what your problem is. Do you want to
integrate g[x] twice, like Integrate[Integrate[g[x],x],x]? What does
x20, x15 e.t.c. mean, are these constants or should it read x^20 ...?
Anyway in both cases Mathematica will integrate without problems.
Daniel
Roger Bagula wrote:
> I have this nasty differential equation: ( Lorentz invariant elliptical
> invariant Klein-Gordon)
> -(hbar2/(2*m))*Sum[D[Phi[x[i]],{x(i),2}],{i,1,4}]+2*m*c2*J{Sqrt[m/m0]]=0
> The substition I'm working with is the Kerr mass one of:
> m/m0->(r/r0)^2
> and J as an elliptical invariant like:
> J[x_]=(-x20+228*x15-494*x10-228*x5-1)3/(1728*x5*(x10+11*x5-1)5)
> I isolate the radial part of the second differential ( in a polar four
> sopace the angular part isn't importyant mostly to mass radial solutions)
> The Phi part is straight forfowd so I'm left with a double interagation
> of a nasty rational function: ( m^2->r^4)
> f[x_]=(-x20+228*x15-494*x10-228*x5-1)3/(1728*x*(x10+11*x5-1)5)
> or if
> hbar^2/(m^2*c^2)-->r^2
> g[x_]=(-x20+228*x15-494*x10-228*x5-1)3/(1728*x^7 *(x10+11*x5-1)5)
> What I tried after the Integration wouldn't stop in my Mathematica
> was doing a term wise integration ( 64 terms, every 5th one non-zero).
>
>