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Re: Mathematica Integration help

• To: mathgroup at smc.vnet.net
• Subject: [mg86156] Re: Mathematica Integration help
• From: Francogrex <franco at grex.org>
• Date: Tue, 4 Mar 2008 02:07:08 -0500 (EST)
• References: <fqetdm$jjs$1@smc.vnet.net> <fqghfq$f5c$1@smc.vnet.net>

On Mar 3, 10:47 am, Jens-Peer Kuska <ku... at informatik.uni-leipzig.de>
wrote:
> look what happens when you compute from:
> res = Integrate[
>    Product[1/(E^((Subscript[x, i] - \[Mu])^2/(2*\[Sigma]^2))*
>        Sqrt[2*Pi*\[Sigma]^2]), {i, 1, n}], \[Mu]]
>
> D[res,\[Mu]]
>
> and see that the result is *not*
>
> Product[1/(E^((Subscript[x, i] - \[Mu])^2/(2*\[Sigma]^2))*
>        Sqrt[2*Pi*\[Sigma]^2]), {i, 1, n}]
>
> this obvious a bug.

The result is:

(1/(E^((\[Mu] - Subscript[x, i])^2/(2*\[Sigma]^2))*Sqrt[\[Sigma]^2]))^
  n/(2*Pi)^(n/2)

Do you mean that it cannot reconstitute the product?

• Follow-Ups:
  • Re: Re: Mathematica Integration help
    • From: Daniel Lichtblau <danl@wolfram.com>