Re: Cancel[] and finite symbolic sums ?
- To: mathgroup at smc.vnet.net
- Subject: [mg102791] Re: [mg102763] Cancel[] and finite symbolic sums ?
- From: "David Park" <djmpark at comcast.net>
- Date: Thu, 27 Aug 2009 06:35:26 -0400 (EDT)
- References: <15915821.1251288036966.JavaMail.root@n11>
You could try something like this:
Sum[W*Subscript[b, k], {k, 1, N}]/W
MapAt[Part[%, 1] # &, Part[%, 2], 1]
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/
From: Andre Holzner [mailto:andre.holzner at gmail.com]
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