Date: Mar 1, 2014 8:12 AM
Author: Jonas Matuzas
Subject: Re: integral for fun

On Friday, February 28, 2014 5:25:57 PM UTC+2, Jean-Michel Collard wrote:
> Le 28/02/2014 15:32, Jonas Matuzas a écrit :
>

> > I wrote integral in Mathematica:
>
> > Integrate[Cos[x]^4/(1 + x^8), {x, -\[Infinity], \[Infinity]}]
>
> >
>
> > for fun,( for speed compassion between win7 and Linux (actual I found that in Linux 4x faster with more simple integrals ))
>
> > and... This integral is still calculating, it is already passed 1.5 day , I am getting curios ... I am gonna to leave it for weekend in work place . My computer is almost front end- (i7 4770, 16 GB RAM), integral is running on Linux.
>
> > I am a bit lazy but I think this integral can by taken with pencil and paper using residual theory.
>
> > I find publication is talking about similar problem , and writing that in this case residual theory is not complete..:
>
> > http://www.csm.ornl.gov/~bowman/fjts312.pdf
>
> >
>
> > What do you think - is it connected with so long calculation time.
>
> > Do you have some thoughts about this case?
>
> > I am just curios :)
>
> >
>
>
>
> Try NIntegrate and you will have the answer in less than a second.


I know that NIntegrate it will do in less then seconds. But this group is ...symbolic. Actually I do not need answer. This is my game. I will not help humanity to live better solving this integral. For me it is just curios - what mathematic is doing so long with a such simple integral ?! And what the answer would be after so long (days)calculation.