Re: Solving a Integral
- To: mathgroup at smc.vnet.net
- Subject: [mg78069] Re: Solving a Integral
- From: ehrnsperger.b at pg.com
- Date: Fri, 22 Jun 2007 06:39:50 -0400 (EDT)
Jean-Marc,
thanks for your help. I made the changes as you suggested and I still can
not convince Mathematica to solve the integral. Any additional
suggestions?
Thanks,
Bruno
Dr. Bruno Ehrnsperger
Principal Scientist
Procter & Gamble Service GmbH
Sulzbacherstr.40
65824 Schwalbach
Germany
fon +49-6196-89-4412
fax +49-6196-89-22965
e-mail: ehrnsperger.b at pg.com
internet: www.pg.com
Gesch=E4ftsf=FChrer: Otmar W. Debald, Gerhard Ritter, Dr. Klaus Schumann,
Willi Schwerdtle
Sitz: Sulzbacher Str. 40, 65824 Schwalbach am Taunus, Amtsgericht:
K=F6nigstein im Taunus HRB 4990
Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
21/06/2007 15:30
To: Bruno Ehrnsperger-B/PGI@PGI, mathgroup at smc.vnet.net
cc:
Subject: Re: Solving a Integral
ehrnsperger.b at pg.com wrote:
> I need help in solving the following integral:
>
> Integral = 1/(beta^alpha* Gamma[alpha]) *
> Integrate[x^(alpha-1)*Exp[-x/beta]/(1+Exp[-a*x-b]),{x,0, infinity},
-----------------------------------------------------------^^^^^^^^
oo Must be written Infinity (with a capital I)
> Assumptions: (alpha> 0)||(beta > 0)||(a > 0)||(b <0)]
-------------^^
The : character means nothing here: use ->
Moreover, are you sure that you want a OR ( that is ||) condition on
your assumptions rather than an AND (that is &&)?
HTH,
Jean-Marc
> The Integral is approximately 1/(beta^alpha* Gamma[alpha])
> *1/(1+Exp[-a*alpha*beta-b]) + Order[alpha*beta^2]
>
> However, I would like to have an exact analytical solution, and I am
> failing to convince Mathematica to give me the solution. Is there a way
to
> ask Mathematica to give the solution as a series expansion of my
> approximate solution?
>
> Thanks so much for your help,
>
> Bruno
>
> Dr. Bruno Ehrnsperger
> Principal Scientist
>
> Procter & Gamble Service GmbH
> Sulzbacherstr.40
> 65824 Schwalbach
> Germany
>
> fon +49-6196-89-4412
> fax +49-6196-89-22965
> e-mail: ehrnsperger.b at pg.com
> internet: www.pg.com
>
> Gesch=E4ftsf=FChrer: Otmar W. Debald, Gerhard Ritter, Dr. Klaus
Schumann,
> Willi Schwerdtle
> Sitz: Sulzbacher Str. 40, 65824 Schwalbach am Taunus, Amtsgericht:
> K=F6nigstein im Taunus HRB 4990
>
>