# equations solve

• Sep 28th 2011, 07:08 AM
borok
equations solve
hello
i have 5 equation and 5 unknown variable (x, y,z,T4,q)
i can not solve these five equation and i was very confused thanks if you help me
i too tried to solve this problem by matlab and maple software but didn't succeed
i have final result but i want processes

thanks so much
• Sep 29th 2011, 05:36 PM
Ackbeet
Re: equations solve
Hmm. Given the extreme complexity of your equations, I quite doubt that anyone here on MHF is going to take the time to slog through it all. I can tell you this: in Mathematica, the commands you'd probably use might look something like this:

epsilon = ...
R = ...
L = ...
Solve[{D[L,x]==0,D[L,y]==0,D[L,z]==0,D[L,T4]==0},{x,y,z,T4,q}]

I do have one question: it does not seem to me that you have enough equations to solve for all five variables. I see four equations - the ones involving the derivatives. That is, you'd plug in the definitions of epsilon and R into the L equation. So that's essentially one equation defining L. But L is really an "unknown", so that doesn't help you get down to the five variables you're after. Then, you impose the four derivative conditions, so that's four equations. Your "fifth" equation is merely a restatement of the definition of epsilon, so it doesn't add any new information. You might be able to solve parametrically for your variables, but that's about it, unless you've got another equation up your sleeve that you didn't give us.
• Sep 30th 2011, 12:45 AM
borok
Re: equations solve
Quote:

Originally Posted by Ackbeet
Hmm. Given the extreme complexity of your equations, I quite doubt that anyone here on MHF is going to take the time to slog through it all. I can tell you this: in Mathematica, the commands you'd probably use might look something like this:

epsilon = ...
R = ...
L = ...
Solve[{D[L,x]==0,D[L,y]==0,D[L,z]==0,D[L,T4]==0},{x,y,z,T4,q}]

I do have one question: it does not seem to me that you have enough equations to solve for all five variables. I see four equations - the ones involving the derivatives. That is, you'd plug in the definitions of epsilon and R into the L equation. So that's essentially one equation defining L. But L is really an "unknown", so that doesn't help you get down to the five variables you're after. Then, you impose the four derivative conditions, so that's four equations. Your "fifth" equation is merely a restatement of the definition of epsilon, so it doesn't add any new information. You might be able to solve parametrically for your variables, but that's about it, unless you've got another equation up your sleeve that you didn't give us.

1.thanks so much dear friend
2.my problem equations is 5 (epsilon and derivatives) and final results aren't exact number (for example x=10 y=20 z=30,..) so final results are parametric by epsilon
(x(e),y(e),...)
3.The final results are listed in Attachment except q
4.this problem is for one article that (Chinese is written)
• Sep 30th 2011, 06:46 AM
Ackbeet
Re: equations solve
Quote:

Originally Posted by borok
1.thanks so much dear friend
2.my problem equations is 5 (epsilon and derivatives) and final results aren't exact number (for example x=10 y=20 z=30,..) so final results are parametric by epsilon
(x(e),y(e),...)
3.The final results are listed in Attachment except q
4.this problem is for one article that (Chinese is written)

You're welcome for whatever help I could provide. I'm not sure if I've helped all that much, but I would agree that you're still going to have a parameter remaining - epsilon is a perfectly good one.