Re: Limit of an Integer Function
- To: mathgroup at smc.vnet.net
- Subject: [mg18839] Re: [mg18767] Limit of an Integer Function
- From: BobHanlon at aol.com
- Date: Thu, 22 Jul 1999 22:57:42 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Phil,
For the example given, you do not need the limit, you need Mathematica to
make use of the fact that n is an integer. In version 4, Simplify with the
conditional that n is an element of the integers:
Simplify[Sin[n Pi], Element[n, Integers]]
0
Bob Hanlon
In a message dated 7/20/99 8:12:40 AM, mend0070 at tc.umn.edu writes:
>I seem to have found a blind spot in my knowledge of how to get
>Mathematica to evaluate limits.
>
>I want to evaluate the limit of a function where the domain is a member
>of the Natural numbers, such as infinite series. It seems that Limit
>assumes that the function is continuous.
>
>For example, if I asked
>
>Limit[Sin[ n Pi ],n-> Infinity], mathematica would return:
>Interval[{-1,1}]. This is true if n is a member of the Reals, but not
>true if n is a positive integer (in which case the limit would be 0.]
>
>Is there another function I should use? Or would it be nice to specify
>the domain of the function as a feature request?
>