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Wrong result for definite integral

  • To: mathgroup at smc.vnet.net
  • Subject: [mg109954] Wrong result for definite integral
  • From: Matthias <ichschmidt at gmx.net>
  • Date: Wed, 26 May 2010 07:09:17 -0400 (EDT)

Dear all,

I get a wrong, complex value for the following definite integral:

In[27]:= Integrate[(1/x - 1/x/E^x)*
         PDF[NormalDistribution[1, 2], x], {x, -Infinity, Infinity}]

Out[27]= -((I Sqrt[\[Pi]])/(Sqrt[2] E^(1/8)))


Numerical Integration gives the following correct result:

In[25]:= NIntegrate[(1/x - 1/x/E^x)*
  PDF[NormalDistribution[1, 2], x], {x, -100, 100}]

Out[25]= 1.25243

This result does not depend on the integration bounds. Does anybody have
an idea what's going wrong?

Thanks,
Matthias


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