Re: System of differential equations
- To: mathgroup at smc.vnet.net
- Subject: [mg13596] Re: System of differential equations
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Mon, 3 Aug 1998 03:53:55 -0400
- Organization: University of Western Australia
- References: <6puhnm$6r2@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Jens-Peer Kuska wrote:
> Your problem is solved with
>
> eqn={a y[z]-b s'[z]==0,d s[z]+f y'[z]+g s'[z]+h s''[z]==0}
>
> deqn=Append[eqn,D[#,z] & /@ eqn[[1]]]
>
> Eliminate[deqn,{y[z],y'[z]}]
An alternative, which avoids having to work out which equation to
differentiate, is
eqn={a y[z]-b s'[z]==0,d s[z]+f y'[z]+g s'[z]+h s''[z]==0}
deqn = Flatten[{eqn, D[eqn, z]}];
Eliminate[deqn, {y[z], y'[z], y''[z]}]
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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