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MathGroup Archive 2006

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Re: differential equation solve

  • To: mathgroup at smc.vnet.net
  • Subject: [mg68862] Re: [mg68821] differential equation solve
  • From: "Chris Chiasson" <chris at chiasson.name>
  • Date: Mon, 21 Aug 2006 03:28:30 -0400 (EDT)
  • References: <200608200843.EAA04364@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

You must have a definition for y or another variable already assigned
in the same session.
Clear[x,y,r,a]; then solve the equation.

On 8/20/06, elvis <rapstone at gmail.com> wrote:
> Here we often use mathematica to solve differential equations, when I
> encouter a equation with several constrains I set them to those values.
> But it cannot solve it and have the following warnings:
>
>     DSolve::deqx: Supplied equations are not differential equations of
> the given functions.
>
> Give a very simple differential equation here:
>
>   DSolve[{y'[x] == r*y[x], y[0] == a}, y, x]
>
> another equation:
>
> \!\(DSolve[{\(x'\)[t] == r*x[t] \((1 - x[t]\/xm)\), x[0] == x0}, x,
> t]\)
>
> this face anothe prolbem
>
> Can anyone help to "solve" this problem for me?
> Thanks!
>
>


-- 
http://chris.chiasson.name/


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