Re: Cancel[] and finite symbolic sums ?
- To: mathgroup at smc.vnet.net
- Subject: [mg102802] Re: [mg102763] Cancel[] and finite symbolic sums ?
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Thu, 27 Aug 2009 06:37:36 -0400 (EDT)
- Reply-to: hanlonr at cox.net
s = Sum[W*Subscript[b, k], {k, 1, N}]; To divide each term by W: s /. Sum[x_, iter_] :> Sum[x/W, iter] Sum[Subscript[b, k], {k, 1, N}] Bob Hanlon ---- Andre Holzner <andre.holzner at gmail.com> wrote: ============= Dear experts, I wonder what I'm doing wrong here... I try to simplify the following expression: [Sum[W * Subscript[b, k], {k, 1, N}]/W by doing Cancel[Sum[W * Subscript[b, k], {k, 1, N}]/W] it looks like Mathematica just returns me the original expression: Sum [W*Subscript[b, k], {k, 1, N}]/W When I try a sum over b instead of Subscript[b, k], it seems to work as expected: Cancel[Sum[W * b, {k, 1, N}]/W] gives: b*N Any ideas what I'm doing wrong ? thanks, Andre