Re[2]: Eliminating unknown functions from partial differential equations
- To: mathgroup at smc.vnet.net
- Subject: [mg41085] Re[2]: [mg41039] Eliminating unknown functions from partial differential equations
- From: Stepan Yakovenko <yakovenko at ngs.ru>
- Date: Thu, 1 May 2003 05:00:35 -0400 (EDT)
- References: <125.2139e18a.2be1d7bf@aol.com>
- Reply-to: Stepan Yakovenko <yakovenko at ngs.ru>
- Sender: owner-wri-mathgroup at wolfram.com
Hello BobHanlon,
Thursday, May 1, 2003, 8:51:59 AM, you wrote:
Bac> eqn = {x'[t]==y[t], y'[t]==-x[t]};
Bac> Reduce[Join[eqn,D[#,t]& /@ eqn], x[t], NestList[D[#,t]&, y[t], 2]]
Bac> -Derivative[2][x][t] == x[t]
Bac> DSolve[%, x[t],t]
Oh, I don't need to solve my system. I just want to get rid of one of
the unknowns. Please take a look at one of my examples.
--
Best regards,
Stepan mailto:yakovenko at ngs.ru