Re: Series holding the final sum
- To: mathgroup at smc.vnet.net
- Subject: [mg117791] Re: Series holding the final sum
- From: Heike Gramberg <heike.gramberg at gmail.com>
- Date: Thu, 31 Mar 2011 04:04:08 -0500 (EST)
It's probably cheating a little, but what about
(Sum[(-1)^(n + 2) x^(2 n + 1)/(2 n + 1), {n, 0, 5}] /. x -> -y) /.
y -> HoldForm[1]
Heike
On 30 Mar 2011, at 11:10, Jon Joseph wrote:
> All: Given the following sum:
>
> Sum[(-1)^(n + 2) x^(2 n + 1)/(2 n + 1), {n, 0, 5}]
>
> which generates:
>
> x - x^3/3 + x^5/5 - x^7/7 + x^9/9 - x^11/11
>
> I would like to replace x with -1 (%/.x->-1) without the sum being evaluated so I end up with
>
> -1+1/3-1/5+1/7-1/9+1/11
>
> So far I have not been able to find a way to Hold, HoldForm, Unevaluate, or Defer and keep getting -2578/3465. Thanks. Jon
>