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Article #20

Re: tre serie (tres series)

#20
From: Dr. Wolfgang Hintze
Date: Sun, 06 Nov 2011 08:29
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"Dr. Wolfgang Hintze" <weh@snafu.de> schrieb im Newsbeitrag 
news:9hmci0Fj94U1@mid.uni-berlin.de...
>
> "Ignacio Larrosa Ca�estro" <ilarrosaQUITARMAYUSCULAS@mundo-r.com> 
> schrieb im Newsbeitrag news:9hkhdgFqm6U1@mid.individual.net...
>> superpollo wrote:
>>> A = sum(1/((2n-1)(3n-1)),n,1,inf)
>>
>> rq(3)pi/6 - ln(27/16)/2
>>
>>> B = sum(1/((2n-1)(4n-1)),n,1,inf)
>>
>> pi/4 - ln(2)/2  (esta es la m�s f�cil)
>>
>>> C = sum(1/((3n-1)(4n-1)),n,1,inf)
>>
>> 3ln(3/4)/2 + pi(3 - rq(3))/6
>>
>> Hoy estar� fuera todo el dia, ma�ana lo justifico si nadi4e lo ha 
>> hecho antes.
>>
>>
>> -- 
>> Saludos,
>>
>> Ignacio Larrosa Ca�estro
>> A Coru�a (Espa�a)
>> ilarrosaQUITARMAYUSCULAS@mundo-r.com
>> http://www.xente.mundo-r.com/ilarrosa/GeoGebra/
>
> Estoy en el camino de estudiar los productos
>
> pA (x) = Product ( 1 - x/((2n-1)(3n-1),(n,1,oo) ) = Product ( 1 - 
> x/((2n+1)(3n+2),(n,0,oo) )
> pB (x) = Product ( 1 - x/((2n-1)(4n-1),(n,1,oo) ) = Product ( 1 - 
> x/((2n+1)(3n+3),(n,0,oo) )
> pC (x) = Product ( 1 - x/((3n-1)(4n-1),(n,1,oo) ) = Product ( 1 - 
> x/((3n+2)(4n+3),(n,0,oo) )
>
> o m�s generalmente
>
> para k>1, m>1
>
> pG (x) = Product ( 1 - x/((k.n-1)(m.n-1),(n,1,oo) )= Product ( 1 - 
> x/((k.n+(k-1))(m.n+(m-1)),(n,1,oo) ),
>
> Desarollando estos productos por potencias de x nos da en el primero 
> coeficiente las sumas buscadas.
>
> Ahora, los pX(x) son funciones holomorfas (es correcto en 
> castellano?) en x y tienen ceros en los puntos
>
> x = ((k.n+(k-1))(m.n+(m-1)) = (k.m)n^2 -(k+m)n + 1, n=1,2,...
>
> Solucionando la cuadr�tica por n nos da
>
> n1 = (k + m - 2 k m + Sqrt[k^2 - 2 k m + m^2 + 4 k m x])/(2 k m)}
> n2 = (k + m - 2 k m - Sqrt[k^2 - 2 k m + m^2 + 4 k m x])/(2 k m)}}
>
> La funci�n pG(x) tiene ceros en todos los puntos n+ y n- = 0,1,2,...
>
> Por eso podemos sospechar que (Gamma(z) = la funci�n Gamma de Euler, 
> que tiene ceros en z=0,-1,-2, ---)
>
> pG(x) = cte /( (Gamma(-n1(x))(Gamma(-n2(x)) )
>
> donde cte = (Gamma(-n1(x=0))(Gamma(-n2(x=0)) ya que pG(x=0)=1.
>
> Ejemplos
>
> pA(x) = (Sqrt[Pi] Gamma[2/3])/(Gamma[(1/12) (7 - Sqrt[1 + 24 x])] 
> Gamma[(1/12)(7 + Sqrt[1 + 24 x])])
>
> pB(x) = (Sqrt[Pi]Gamma[3/4])/(Gamma[5/8 - (1/8)Sqrt[1 + 8 x]] 
> Gamma[(1/8)(5 + Sqrt[1 + 8x])])
>
> pC(x) = (Gamma[2/3]Gamma[3/4])/(Gamma[(1/24)(17 - Sqrt[1 + 48 x])] 
> Gamma[(1/24)(17 + Sqrt[1 + 48 x])])
>
> ... tengo que acabar con eso por el momento...
>
> Saludos,
> Wolfgang

Me corrijo:

(Gamma(z) = la funci�n Gamma de Euler, que tiene ceros en 
z=0,-1,-2, ---)

deber�a haber le�do
(Gamma(z) = la funci�n Gamma de Euler, que tiene *polos simples* en 
z=0,-1,-2, ...)

y a�ado:

Por lo tanto 1/Gamma(z) es cero en z = 0, -1, -2, ...

Saludos,
Wolfgang
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From: "Dr. Wolfgang Hintze" <weh@snafu.de>
Newsgroups: it.scienza.matematica,es.ciencia.matematicas
Subject: Re: tre serie (tres series)
Date: Sun, 6 Nov 2011 09:29:21 +0100
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