Re: Trouble with Limit[I ... k]/k, k-> Infinity]
- To: mathgroup at smc.vnet.net
- Subject: [mg56160] Re: Trouble with Limit[I ... k]/k, k-> Infinity]
- From: Peter Pein <petsie at arcor.de>
- Date: Sun, 17 Apr 2005 03:07:05 -0400 (EDT)
- References: <d3qgs6$oao$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Christian Mikkelsen wrote:
> I am struggling to valuate an intermediate result in a long calculation
> and I get stuck with terms like this one:
>
> Limit[Exp[I k A]/k, k -> Infinity, Assumptions -> {A != 0, A \[Element]
> Reals}]
>
> In the actual expression, A are somewhat more complicated expressions but
> I am willing to tell Mathematica by hand that they are real and
> non-zero, however, it still doesn't work. I don't see that there is a
> problem in mathematical terms so how can I convince Mathematica to
> give me an answer?
>
> Actually, Mathematica 5.1 does not mind telling me the result of
>
> Limit[Exp[I k]/k, k -> Infinity]
>
> At the moment I am relying on a kludge relying on pattern-matching but I
> am not very good at it so there might be a point to help me on.
> Any input or help will be greatly appreciated.
>
>
> Thanks,
>
> Christian
>
Union[Limit[
Exp[I k A]/k, k -> Infinity, Assumptions -> #] & /@ {A > 0, A < 0}]
--
Peter Pein
Berlin