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How can I solve these simultaneous quadratic equations in Mathemetica?

• To: mathgroup at smc.vnet.net
• Subject: [mg65726] How can I solve these simultaneous quadratic equations in Mathemetica?
• From: Heisnam Singh <thoihen at yahoo.com>
• Date: Sun, 16 Apr 2006 03:48:53 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

[This post has been delayed due to email problems - moderator]

Hello,

I am trying to solve a set of  4 simultaneous quadratic equations in 4 unknowns (plus a paramter, c) using Mathematica. I tried doing the following:

Solve[{1 + 3c/2 + x(1 + c + y + z - x) + c*y + (y + z + x)/2 - w(2y + 2x-3w + 3 + 2c) == 0,  c/2 + w(y + z - w + 3/2 + c) - x( 2w + 2z - 3x + 2) == 0, 
1 + 2c + w(1 + c) + z(w + x - z + 3/2 + c) - y(2w + 2z - 3y + 4 + 2c) == 0, y(x + w - y + 1 + c) - c(1 + w) + (y + w - x)/2 - z(2y + 2x - 3z) == 0}, {w, x, y, z}]

I need only real solutions (actually only positive real numbers if it exist). I have also tried using Reduce[{eqns},{vars},reals]. But both Solve and Reduce do not seem to be able to give any solutions. (I get an error message saying that there's not enough memory and that mathematica has shut down). Is there a command or a way to solve such system of equations using Mathematica. Please help. ( I haven't tried Nsolve. Can it solve the above? )

thank you in advance.
Thoihen

• Follow-Ups:
  • Re: How can I solve these simultaneous quadratic equations in Mathemetica?
    • From: Daniel Lichtblau <danl@wolfram.com>