Re: 4th order DE, NDSolve no solution, why?
- To: mathgroup at smc.vnet.net
- Subject: [mg15813] Re: 4th order DE, NDSolve no solution, why?
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Mon, 8 Feb 1999 03:25:39 -0500 (EST)
- Organization: University of Western Australia
- References: <79jcmg$r4a@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Kevin J. McCann wrote:
> That is the first I have seen. Wonder where I got the idea? I guess I
> was thinking about eigenvalue problems like
>
> y''[x] + y[x] == 0, y[0]==0,y[1]==0
>
> Which NDSolve will do, but it gives y=0 only, not all of the other
> possibilities.
Actually, NDSolve is correct to return y=0 for this problem. However, I
think you are thinking of
DSolve[{y''[x]+y[x]==0, y[0]==0, y[Pi]==0}, y[x], x]
which NDSolve can solve. However, it does not return the general
solution to
DSolve[{y''[x]+ n^2 y[x]==0, y[0]==0, y[Pi]==0}, y[x], x]
Cheers,
Paul
____________________________________________________________________
Paul Abbott Phone: +61-8-9380-2734
Department of Physics Fax: +61-8-9380-1014
The University of Western Australia Nedlands WA 6907
mailto:paul at physics.uwa.edu.au AUSTRALIA
http://www.physics.uwa.edu.au/~paul
God IS a weakly left-handed dice player
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