Re: Solution of this equation
- To: mathgroup at smc.vnet.net
- Subject: [mg20700] Re: [mg20629] Solution of this equation
- From: "Kevin J. McCann" <kevinmccann at Home.com>
- Date: Mon, 8 Nov 1999 02:48:45 -0500
- References: <8037bu$adu@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
The problem is based on the Maxwell construction in thermodynamics. At a given reduced temperature Tr there are 3 real roots for only a limited range of reduced pressures. In general the roots are complex. Kevin <BobHanlon at aol.com> wrote in message news:8037bu$adu at smc.vnet.net... > Dave, > > Whether or not the solutions are all real or the imaginary parts are very > small will depend on the values of Pr and Tr. [Note that Tr is a protected > symbol name for the trace of a matrix or tensor list.] > > If you are solving this with specific values and the imaginary parts are > truly small, then use Chop. > > Bob Hanlon > > > In a message dated 11/4/1999 8:04:15 AM, dhr at glue.umd.edu writes: > > >Can anyone offer insight here? > > > >This Mathematica expression gives 3 solutions to the equation. > > > >Solve[Pr == (8*Tr)/(3*vr - 1) - 3/vr^2, vr] > > > > > >The problem is that there are 3 Real solutions, and Mathematica is giving > >solutions with (granted a small) imaginary component. > > > >And hitting it with a full simplify is just not a good idea... > > >