Re: Solving a Integral
- To: mathgroup at smc.vnet.net
- Subject: [mg78125] Re: Solving a Integral
- From: dimitris <dimmechan at yahoo.com>
- Date: Sat, 23 Jun 2007 07:14:20 -0400 (EDT)
- References: <f5dkds$no$1@smc.vnet.net>
I think tour integral
does not have a closed form
solution (at least using Mathematica
for evaluating!).
Did you search some of the well known
collections of integral tables?
Dimitris
ehrnsperge... at pg.com :
> 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},
> Assumptions: (alpha> 0)||(beta > 0)||(a > 0)||(b <0)]
>
> 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
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