DSolve bug in Mathematica version 4.1?,
- To: mathgroup at smc.vnet.net
- Subject: [mg27924] DSolve bug in Mathematica version 4.1?,
- From: "SANCHEZ DE LEON, Guillermo" <gsl at fab.enusa.es>
- Date: Sat, 24 Mar 2001 00:48:52 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I have check the System of Differential Eq. (from the book VisualDSolve by
S.Wagon: ) that follow with different Math version.
In vers 2.1 and 2.2 I obtain the fine solution.
In vers. 3.0.0 don't work.
In vers. 4.0 work using N[].
In vers. 4.1 don`t work.
Any suggestion to obtain the solution with Math 4.1 using DSolve (I know
others way to solve the system)
a12 = 0.0124; a21 = 0.0111; a31 = 0.0039; a13 = 0.000035; a41 = 0.0211;
a42 = 0.0162; inputPb = 49.3;
LeadFlowEqns = {x'[t] == -(a41 + a21 + a31) x[t] + a12 y[t] + a13 z[t] +
inputPb, y'[t] == a21 x[t] - (a42 + a12) y[t],
z'[t] == a31 x[t] - a13 z[t]};
DSolve[Join[LeadFlowEqns, {x[0] == 0, y[0] == 0, z[0] == 0}], {x[t], y[t],
z[t]}, t]
In Math 4.1 I receive the message
DSolve::"bvnul": "For some branches of the general solution, the given
\boundary conditions lead to an empty solution."
{ }