Re: system of simultaneous equations
- To: mathgroup at smc.vnet.net
- Subject: [mg22914] Re: system of simultaneous equations
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 6 Apr 2000 02:04:31 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <8ce9en$12i@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
let us make some equations:
eqn = {x^2 + y + z == 1,
x + y^2 + z == 1,
x + y + z^2 == 1}
solve it:
sol = Solve[eqn, {x, y, z}]
and now comes the answer:
Select[{x, y, z} /. sol, And @@ ( Positive /@ #) &]
Hope that helps
Jens
David Braunholtz wrote:
>
> WHile I've got the attention of a Mathematica expert, I am wanting to
> select a single root of a system of simultaneous equations (with
> positive values for all 3 variables) - and (being new to mathematica)
> cannot work out how to do this. I successfully get a list of roots, but
> cannot make the (you would think) easy step to reduce the list to
> only (positive) roots. Any help VERY gratefully received. I have
> searched in Mathgroup at Wolfram without finding anything.