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Re: little brain teaser
Posted:
Sep 16, 1996 2:39 PM


On Fri, 13 Sep 1996, Jerry Clark wrote:
> Dr. H.M.A. Winand wrote: > > > > Dear All, > > > > Any idea on how to solve this little brain teaser without having a > > seriestype solution? > > > > Integrate[Exp[(a^2 x^2)/2] Erf[k x], {x,y,Infinity}] > > > > where a and k are real, y takes values from Infinity to +Infinity, but is > > generally within +/3. > > > > Any help would be greatly appreciated, and replies can also be emailed > > to: Prof. D. J. Whitehouse, djw@eng.warwick.ac.uk or to my address. > > > > Best regards, > > > > Dr. Henri M.A. Winand > > > > P.S. If you wish to propagate this to other mathtype newsgroups, etc., > > feel free to do so...both the handandpaper and Mathematica solutions > > will not give us what we want (i.e. an exact sol. without series). > > er.. what's Erf? Is it something Cockneys spread on their gardens? > Please explain. > > JC > >
Jerry,
Well, Erf[x] stands for 'error function'. That is to say, the integral of the Gaussian distribution given by:
Erf[x] := (2/SQRT[Pi]) * Integrate[Exp[t^2],{t,0,z}].
I hope this helps,
Henri



