Re: system of nonlinear equations in mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg72288] Re: system of nonlinear equations in mathematica?*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Mon, 18 Dec 2006 06:56:11 -0500 (EST)*Organization*: The Open University, Milton Keynes, UK*References*: <em3a4g$7f0$1@smc.vnet.net>

pilly4u wrote: > Hai all, > > I am tryign to solve a system of nonlinear differential equations using mathematica.I think there exists singularity in my equations and am new to mathematica and donoy know i to get the problem resolved.Please help me out in this.thought to attach my equations here which i couldnt do.please do reply me through email to saihone at gmail.com. > > 0.5(derivative(f)+x(derivative(derivative(x))= - derivative(0.1*k^2/d(derivative(derivative(f)))); > > -10(k+0.5*x*derivative(k)) = derivative(0.1*k*k*derivative(k)/d) + 0.1*k^2*(derivative(derivative(f))^2/d - d; > > 10(-2d-derivative(d)*x/2) = derivative(0.1*k^2*derivative(d)/d) + 0.144*k*(derivative(derivative(f))^2) - 1.92*d^2/k > > the code i wrote is It would be much much better to post your code in InputForm: select the cell(s) you want to include in your email and go to Menu Cell -> Convert To -> InputForm Or you could use the excellent Ingolf Dahl's "SetFaceAndFont" palette. See http://library.wolfram.com/infocenter/MathSource/5752/ > \!\(\* > RowBox[{\(eqdiff1 = 10\/2\ \(f\^â?²\)[x] + \(10\/2\) \(xf\^â?³\)[x] == \(f\^3\)[ ---------------------------------------------------------^^ It seems a space is missing here. I guess you wanted the variable x times the second derivative of the function f; however, as written you declare a new function called xf. <snip> Regards, Jean-Marc