Re: solving 3 eqns and 3 unkwns
- To: mathgroup at smc.vnet.net
- Subject: [mg40935] Re: solving 3 eqns and 3 unkwns
- From: Alois Steindl <Alois.Steindl at jet2web.cc>
- Date: Fri, 25 Apr 2003 08:01:41 -0400 (EDT)
- Organization: Inst. f. Mechanics II, TU Vienna
- References: <b88biv$h5a$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Richard Cochinos <richard at theory.org> writes:
> Hi, I'm trying to get methematica to solve the following equations for
> x,y and z. I can't get anyoutput, what is wrong with the following code?
>
> Solve[{a*P*A*x^(a - 1)*y^b*z^c - r == 0, b*P*A*x^a*y^(b - 1)*z^c - w == 0,
> c*P*A*x^a*y^b*z^(c - 1) - D/(z^2) == 0}, {x, y, z}]
>
>
Hello,
not every possible equation can be solved analytically at all. And I
do not expect any software to solve all solveable problems.
In your problem it might be possible, if you multiply the last
equation by z^2 and then take logarithms, this should give you a
linear system in the new variables log(x), log(y) and log(z).
Alois
--
Alois Steindl, Tel.: +43 (1) 58801 / 32558
Inst. for Mechanics II, Fax.: +43 (1) 58801 / 32598
Vienna University of Technology,
A-1040 Wiedner Hauptstr. 8-10