Re: Re: Incorrect symbolic improper integral

*To*: mathgroup at smc.vnet.net*Subject*: [mg103668] Re: [mg103645] Re: [mg103586] Incorrect symbolic improper integral*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Fri, 2 Oct 2009 08:21:34 -0400 (EDT)*References*: <30167826.1254225639354.JavaMail.root@n11> <200909300903.FAA09670@smc.vnet.net> <200910011038.GAA23569@smc.vnet.net>

Update their version? But that's the right answer... Andrzej Kozlowski On 1 Oct 2009, at 19:38, Curtis Osterhoudt wrote: > Yes, Jason is obviously using 7.0.0. I use that version on a linux > machine, and get what he reported. Wolfram|Alpha also gets Pi/E -- > they need to update their version! > > >> From: jwmerrill at gmail.com [mailto:jwmerrill at gmail.com] >> >> >> Below is a definite integral that Mathematica does incorrectly. >> Thought someone might like to know: >> >> In[62]:= Integrate[Cos[x]/(1 + x^2), {x, -\[Infinity], \[Infinity]}] >> >> Out[62]= \[Pi]/E >> >> What a pretty result--if it were true. The correct answer is \[Pi] >> *Cosh >> [1], which can be checked by adding a new parameter inside the >> argument of Cos and setting it to 1 at the end: >> >> In[61]:= Integrate[Cos[a x]/(1 + x^2), {x, -\[Infinity], \ >> [Infinity]}, >> Assumptions -> a \[Element] Reals] >> >> Out[61]= \[Pi] Cosh[a] >> >> Regards, >> >> Jason Merrill >> >> >> >> > > > -- > ================================== > Curtis Osterhoudt > cfo at remove_this.lanl.and_this.gov > PGP Key ID: 0x4DCA2A10 > ================================== >

**References**:**Re: Incorrect symbolic improper integral***From:*Curtis Osterhoudt <cfo@lanl.gov>