Need Help: 1st order nonlinear differential equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg51215] Need Help: 1st order nonlinear differential equation*From*: Wolfgang_Eggert at gmx.de (Wolfgang)*Date*: Fri, 8 Oct 2004 02:55:24 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I need to solve the following 1st order nonlinear differential equation. I am really stuck. DSolve refuses to give an answer and I need an algebraic solution. Derivative[1][a][Z] == -((1/n + ((r*(n - 1))/(n^2*a[Z]))*((1 - a[Z])*n - (¦Ñ + 2*¦Ä)*Z))/ (r*(n - 1)*((n*(r - 1) - 2*r)/(n^2*a[Z]^2))*Z*((1 - a[Z])*n - ¦Ä*Z))) where \!\({0 ¡Ü a ¡Ü 1, Z ¡Ý 0, n > 2, 1 > ¦Ä > 0, 1 > ¦Ñ > 0, 1 > r > 0, 0 < r < n\/\(n - 2\)}\) Does anybody know how to solve this problem? Has anybody tips how to impose domain restrictions while solving differential equations in Mathematica (version 5.0.1.0.)? Maybe I am thinking slow but I am really in trouble. Any help is greatly appreciated. Thank you for your time. Respectfully; Wolfgang

**Follow-Ups**:**Re: Need Help: 1st order nonlinear differential equation***From:*DrBob <drbob@bigfoot.com>