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Groups > comp.soft-sys.math.mathematica > #1594

Re: from Rumen, MEXICO, petition

From Noqsi <noqsiaerospace@gmail.com>
Newsgroups comp.soft-sys.math.mathematica
Subject Re: from Rumen, MEXICO, petition
Date 2011-04-11 11:07 +0000
Organization Steven M. Christensen and Associates, Inc and MathTensor, Inc.
Message-ID <inundc$2ei$1@smc.vnet.net> (permalink)
References <inpeua$8ul$1@smc.vnet.net>

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On Apr 9, 5:12 am, Rumen Ivanov <rumen5...@yahoo.com.mx> wrote:
> Hello,
>
> 11*Exp[-Es/135]+10.5*Exp[-Es/425]+
> 4.899*Exp[-Es/1754]+ 2.02912  = 0
> Please tell me how Mathematica can solve this equation
> for Es? With the derivatives of "Solve" it is impossible.

As others have pointed out, it has no real solutions. But it appears
to have many complex solutions:

f=11*Exp[-Es/135]+10.5*Exp[-Es/425]+4.899*Exp[-Es/1754]+2.02912

FindRoot[f==0,{Es,500I}]
{Es->-55.0724+546.446 I}

FindRoot[f==0,{Es,2000I}]
{Es->81.4202+2009.63 I}

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Thread

from Rumen, MEXICO, petition Rumen Ivanov <rumen5252@yahoo.com.mx> - 2011-04-09 11:12 +0000
  Re: from Rumen, MEXICO, petition Peter <petsie@dordos.net> - 2011-04-11 11:07 +0000
  Re: from Rumen, MEXICO, petition Noqsi <noqsiaerospace@gmail.com> - 2011-04-11 11:07 +0000
  Re: from Rumen, MEXICO, petition "Stephen Luttrell" <steve@_removemefirst_stephenluttrell.com> - 2011-04-11 11:05 +0000

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