Re: Is it possible to impose a condition on an iterator
- To: mathgroup at smc.vnet.net
- Subject: [mg101563] Re: [mg101499] Is it possible to impose a condition on an iterator
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Fri, 10 Jul 2009 06:45:03 -0400 (EDT)
- Reply-to: hanlonr at cox.net
Sum[a^2 - 3 a/(4 a^2), {a, 1, 20}] - Sum[a^2 - 3 a/(4 a^2), {a, 7, 11}]
69209343871/28217280
Sum[a^2 - 3 a/(4 a^2), {a, Drop[Range[1, 20], {7, 11}]}]
69209343871/28217280
% == %%
True
Bob Hanlon
---- Mauro <mauro at NONOyahoo.com> wrote:
=============
I would like to perform a summation of this type,
Sum[a^2 - 3 a/(4 a^2), {a, 1, 20}]
excluding however some values of the iteratore, I would for instance
like to exclude the values than to greater of 6 and inferior to 12. Is
it possible?
Thanks