Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2011

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Why won't this sum evaluate?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg120594] Re: Why won't this sum evaluate?
  • From: Gary Wardall <gwardall at gmail.com>
  • Date: Sat, 30 Jul 2011 06:01:42 -0400 (EDT)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <j0oopr$kse$1@smc.vnet.net>

On Jul 27, 5:20 am, PAR123 <reiser.p... at gmail.com> wrote:
> In[120]:= $Version
> Out[120]= "7.0 for Mac OS X x86 (32-bit) (January 30, 2009)"
>
> In[122]:= Sum[c^n/(1 + c^(2*n)), {n, 1, Infinity}]
> Out[122]= -(1/4) + 1/4 EllipticTheta[3, 0, c]^2
>
> In[123]:= Sum[c^n/(1 + c^(2*n)), {n, 0, Infinity}]
> Out[123]= (won't simplify)
>
> The only thing different in the two sums is that the second sum is from 0 to Infinity rather than 1 to Infinity. Clearly, the n=zero term is 1/2.
>
> I have tried various Regularizations and Methods, (not exhaustively) but none seem to work on either of the sums, much less the last.
>
> A side problem - Is there a way to determine what Regularization and Method were used when none were specified?
>
> Thanks


I'm using the latest Mac version 8 and I get the same results as you
do.

Gary Wardall




  • Prev by Date: Cumulative probability question
  • Next by Date: extra lines in framed plots?
  • Previous by thread: Why won't this sum evaluate?
  • Next by thread: Re: Why won't this sum evaluate?