Re: Integral involving erfc and j1

*To*: mathgroup at smc.vnet.net*Subject*: [mg26438] Re: Integral involving erfc and j1*From*: Shaun Roe <shaun.roe at cern.ch>*Date*: Thu, 21 Dec 2000 01:51:40 -0500 (EST)*Organization*: CERN - European Laboratory for Particle Physics*References*: <91pfr4$5kj@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I had a similar problem integrating erfc^2 multiplied by a gauss...in my case it gave the wrong numerical answer as long as the limits were infinite; what I did in the end was to write it with large but finite limits, which gave me the correct answer. (I checked the behaviour by varying the limits to make sure) For an analytical expression I resorted to the old-fashioned way and looked it up in a big book of integrals -- Shaun Roe > From: Rod <rodolphe6831 at my-deja.com> To: mathgroup at smc.vnet.net > Organization: Steven M. Christensen and Associates, Inc and MathTensor, Inc. > Newsgroups: comp.soft-sys.math.mathematica > Date: 20 Dec 2000 00:24:52 -0500 > Subject: [mg26438] Integral involving erfc and j1 > > Mathematica fails to solve the following integral > > Integrate[Erfc[a x] j1[x]^2/x,{x,0,inf}] > > where > > j1[x_]=Sqrt[Pi/(2 x)] BesselJ[3/2,x] > > How can i make it do the work ? > -- > __ _ > / / (_)__ __ ____ __ > / /__/ / _ \/ // /\ \/ / . . . t h e c h o i c e o f a > /____/_/_//_/\_,_/ /_/\_\ G N U g e n e r a t i o n . . . > > > Sent via Deja.com > http://www.deja.com/ >