Problems with DSolve
- To: mathgroup at smc.vnet.net
- Subject: [mg119654] Problems with DSolve
- From: David King <drdavidbking at gmail.com>
- Date: Thu, 16 Jun 2011 04:01:05 -0400 (EDT)
Hello Mathematica Forum, I am a new forum contributer, so it is nice to meet you. I was hoping at least one of you could help me out. I am attempting to find an exact solution to a system of differential equations I type in the following Dsolve function: sol=DSolve[{x'[t] -(0.355+(0.645t/(t+223.06)))x[t]+0.311y[t] +0.046z[t] - 0.149x[t] -0.259x[t],y'[t] 0.149x[t] - 0.311y[t],z'[t] 0.259x[t] -0.046z[t],x[0] D,y[0] 0,z[0] 0}, {x[t],y[t],z[t]},t] So far, Mathematica returns the following: Out[7]:= DSolve[{x=A2[t] -0.408 x[t]+(-0.355-(0.645 t)/(223.06 +t)) x[t] +0.311 y[t]+0.046 z[t],y=A2[t] 0.149 x[t]-0.311 y[t],z=A2[t] 0.259 x[t]-0.046 z[t],x[0] D,y[0] 0,z[0] 0},{x[t],y[t],z[t]},t] Which is what my question is.... This is kind of like asking "Who's on first?" and mathematica answers: "Who's on first." Which is what my question is.... I am pretty sure that my syntax is correct. Anyway, I was hoping that you might be able to knock this one out of the park. I have a numerical solution, just not an exact solution.
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