Re: Integration bug
- To: mathgroup at smc.vnet.net
- Subject: [mg38335] Re: Integration bug
- From: Ray <rayfg at optonline.net>
- Date: Thu, 12 Dec 2002 01:36:11 -0500 (EST)
- References: <at4cv9$eta$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Have no idea why it is doing this but interesting to note that if you
replace d by a specific value you always seem to get Pi rather than 0 as
an answer. Also, you might want to look at the integals from 0 to
Infinity and -Infinity to 0 (the latter is especially messy for a
specific value of d). Maybe a clue there.
David W. Cantrell wrote:
> Using version 4.1,
>
> Integral[Sin[x+d]/(x+d),{x,-Infinity,Infinity}] yields 0 .
>
> This is, of course, incorrect. (Does version 4.2 make this error also?)
>
> Mathematica does Integral[Sin[x]/x,{x,-Infinity,Infinity}] correctly
> however, yielding Pi, which should also be the answer for the original
> integral (regardless of the value of d).
>
> Does anyone have an idea why Mathematica gets the original integral wrong?
>
> David Cantrell
>