• To: mathgroup at smc.vnet.net
• Subject: [mg37265] Quadratic non-linear ODE.
• From: Estudiante Uruguayo <estudfis at yahoo.com.au>
• Date: Mon, 21 Oct 2002 02:29:30 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

```Hi, how are you? We are almost graduated physics
students from south america. Due to our final work,
certain coupled non-linear ODE systems have appear,
and we don't have any idea about how to resolve it,
in spite we attempt to. For our purposes, we would
need
analytical solutions -if there exist- for the
following systems,

dx/dt = ax^2 + by^2
dx/dt = cx^2

dx/dt = axy + by^2
dy/dt = cxy + dx^2

Where a, b, c and d are known constants paremeters
of the problem. We would be very grateful if you can
help us with this matter. We were able to fit
numerically the solutions for both systems, in a
relatively wide range of values, but we did not find
anything aboout the analytical solutions for none of
the systems. In brief words, for our work we would
need the explicit expressions for x(t) and y(t), if
they are known, of course. If you can help us, please

estudfis at yahoo.com.au

We are very grateful, since this moment.
Sincerely,

Javier Krshpa Sánchez and Héctor Rivera
Firpo

Montevideo,Uruguay.

http://careers.yahoo.com.au - Yahoo! Careers
- 1,000's of jobs waiting online for you!

```

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