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Re: system of nonlinear ODE

• To: mathgroup at smc.vnet.net
• Subject: [mg23735] Re: system of nonlinear ODE
• From: "Gartek" <bgarda at uci.agh.edu.pl>
• Date: Mon, 5 Jun 2000 01:09:27 -0400 (EDT)
• Organization: University of Mining & Metallurgy
• References: <8gv85p$5mt@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

I do not understand

1.                           f'''(x)+2.4f(x)f''(x)-0.8(f')**2+z=0
 what is (f')**, and should be z(x) insted of z and should be == insted of
= - that proble touches all equations.

2.                         z''(x)+2.4Pr[f(x)z(x)]'=0
What is Pr function - I see it first time and even checked it in help
browser end didn't find.

3.                        z(0)=0, z'(0)=0, f''(0)=0, f(0)=0, f'(10)=0

Mathematica (r) has some exeption while the NDSolve function is being used
the inital condition has to have the same paramets (usually the same time
for example) if the parameter is 0 then u can not use 10 - f'(10)==0

I am witing for answer!

bgarda at uci.agh.edu.pl



Ioanna Pappa napisa³(a) w wiadomo¶ci: <8gv85p$5mt at smc.vnet.net>...
>Hi
>I am trying to solve a system of two nonlinear ordinary differential
>equations with initial conditions.
>The system
>is
>                           f'''(x)+2.4f(x)f''(x)-0.8(f')**2+z=0
>                          z''(x)+2.4Pr[f(x)z(x)]'=0
>                 with z(0)=0, z'(0)=0, f''(0)=0, f(0)=0, f'(10)=0
>I use NDSolve end the message that gives me is:
>NDSolve::deql:
>The first argument must have both an equation and an initial condition.
>Can you help me;
>Gianna
>ipappa at mie.uth.gr
>
>
>
>