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From: leimkuhl@uiucdcsp.UUCP
Newsgroups: net.math
Subject: Re: Integration problem and solution
Message-ID: <9600005@uiucdcsp.UUCP>
Date: Sun, 17-Feb-85 18:25:00 EST
Article-I.D.: uiucdcsp.9600005
Posted: Sun Feb 17 18:25:00 1985
Date-Received: Tue, 19-Feb-85 08:35:37 EST
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Nf-From: uiucdcsp!leimkuhl    Feb 17 17:25:00 1985





   Actually, there is another simple way to get this:
    
   Make the substitution y1 = 1-x1
                         y2 = 1-x1-x2
                          ...
			 yn = 1-x1-...-xn

   Rewrite the integral under this transformation and integrate
   by parts repeatedly.  The answer pops right out after a few steps.


   This problem and others very similar have been quite common on the
   Putnam exam, and they also occur frequently in probability.  I am
   curious, where did the poser find the problem?