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Re: Question: nonlinear differential equation with boundary conditions

• To: mathgroup at smc.vnet.net
• Subject: [mg26443] Re: Question: nonlinear differential equation with boundary conditions
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Thu, 21 Dec 2000 01:51:45 -0500 (EST)
• Organization: Universitaet Leipzig
• References: <91pjgd$5vc@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

Mathematica can't solve nonlinear boundary value problems.

The online documentation say:

"Not all linear equations with boundary values can 
be solved by the method that is implemented. Nonlinear 
equations cannot be solved, either." 



Regards
  Jens

Ronald Sastrawan wrote:
> 
> Hello!
> Sorry, in my last post there was a mistake in my equation.
> (There should be a y^2 in the equation). The real question was:
> 
> I encountered a problem, trying to numerically solve a differential
> equation.
> My equation looks like:
> 
> A y''[x] - B (y[x])^2 + C Exp[-Dx] == 0
> with boundary conditions: y'[0]==0 , y'[E]==0
> 
> All constants A to E are known.
> 
> Mathematica complains, that the equation is not linear. But in the
> online documentation I saw many examples of nonlinear differential
> equations, which all work fine. What is the difference between the
> examples and my equation ? And is there a possibility to NDSolve my
> equation ?
> 
> Any hint on this would be of great help to me.
> 
> Thanks a lot,
> 
> Ronald
> 
> --
> Ronald Sastrawan
> 
> Freiburg Materials Research Center
> Stefan-Meier-Str. 21
> D-79104 Freiburg
> Germany
> Tel: ++49/761/203-4802
> FAX: ++49/761/203-4801
> EMAIL: sastra at fmf.uni-freiburg.de
> http://www.fmf.uni-freiburg.de/~biomed/FSZ/forschung-FSZ.html