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Re: "Solve[x==Erf[x], x]"

  • To: mathgroup at smc.vnet.net
  • Subject: [mg16519] Re: "Solve[x==Erf[x], x]"
  • From: Vesa-Matti Sarenius <sarenius at student.oulu.fi>
  • Date: Tue, 16 Mar 1999 04:00:00 -0500
  • Organization: University of Oulu
  • References: <7cd7ff$o7s@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

> When I enter this equation, mathematica tells me:
> "Solve:tdep: The equations appear to involve transcendental functions of
> the variables in an essentially non-algebraic way."
> 
> Can you tell me how to get around this problem an solve equations like
> x = 1 - Erf [x]

As Mathematica stated, the equation is in trascendental form. So
x=Erf[x] might be the simplest implicit form of that solution. You
should know that Erf is an intergral that has no closed form solution.
This might help you think why the equation has no simpler solution. 

Try NSolve, with that you'll get some numeric solutions.

-- 
Vesa-Matti Sarenius             *  - Am I a man or what? - A What!*
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