From: Maury Barbato on
Hello,
consider the infinite product

product_{n=1}^Infty [1 + (n^(-2))],

which is easily seen to converge taking the logarithm.
Someone knows th exact value of the product?


Thank you very much for your attention.
My Best Regards,
Maury Barbato
From: David W. Cantrell on
Maury Barbato <mauriziobarbato(a)aruba.it> wrote:
> Hello,
> consider the infinite product
>
> product_{n=1}^Infty [1 + (n^(-2))],
>
> which is easily seen to converge taking the logarithm.
> Someone knows th exact value of the product?

sinh(pi)/pi

David
From: A N Niel on
In article <20100412134614.421$wX(a)newsreader.com>, David W. Cantrell
<DWCantrell(a)sigmaxi.net> wrote:

> Maury Barbato <mauriziobarbato(a)aruba.it> wrote:
> > Hello,
> > consider the infinite product
> >
> > product_{n=1}^Infty [1 + (n^(-2))],
> >
> > which is easily seen to converge taking the logarithm.
> > Someone knows th exact value of the product?
>
> sinh(pi)/pi
>
> David

and, more generally, for any complex z, we have:
sin(pi z) = pi z product(n=1 to infinity)(1-z^2/n^2)
From: Han de Bruijn on
On 12 apr, 20:18, A N Niel <ann...(a)nym.alias.net.invalid> wrote:
> In article <20100412134614.421...(a)newsreader.com>, David W. Cantrell
>
> <DWCantr...(a)sigmaxi.net> wrote:
> > Maury Barbato <mauriziobarb...(a)aruba.it> wrote:
> > > Hello,
> > > consider the infinite product
>
> > > product_{n=1}^Infty [1 + (n^(-2))],
>
> > > which is easily seen to converge taking the logarithm.
> > > Someone knows th exact value of the product?
>
> > sinh(pi)/pi
>
> > David
>
> and, more generally, for any complex z, we have:
> sin(pi z) = pi z product(n=1 to infinity)(1-z^2/n^2)

Wonder if there are OTHER infinite products NOT resemblant to this one
because I've seen this one so many times ..

Han de Bruijn
From: Tonico on
On Apr 13, 10:35 am, Han de Bruijn <umum...(a)gmail.com> wrote:
> On 12 apr, 20:18, A N Niel <ann...(a)nym.alias.net.invalid> wrote:
>
>
>
>
>
> > In article <20100412134614.421...(a)newsreader.com>, David W. Cantrell
>
> > <DWCantr...(a)sigmaxi.net> wrote:
> > > Maury Barbato <mauriziobarb...(a)aruba.it> wrote:
> > > > Hello,
> > > > consider the infinite product
>
> > > > product_{n=1}^Infty [1 + (n^(-2))],
>
> > > > which is easily seen to converge taking the logarithm.
> > > > Someone knows th exact value of the product?
>
> > > sinh(pi)/pi
>
> > > David
>
> > and, more generally, for any complex z, we have:
> > sin(pi z) = pi z product(n=1 to infinity)(1-z^2/n^2)
>
> Wonder if there are OTHER infinite products NOT resemblant to this one
> because I've seen this one so many times ..
>
> Han de Bruijn-

Wonder no more, my dear HdB:

http://pi.physik.uni-bonn.de/~dieckman/InfProd/InfProd.html#InfinitexProducts

You're welcome ( this googling thingy is marvelous...;) )

Tonio