Talk:Residue theorem

Can somebody put the proof of the residue theorem in this page?

--130.207.180.90 01:43, 7 September 2005 (UTC)Arun

The joke was pointless therefore you are pointlesss

So I removed youuu.

The joke is in a mathematics journal

So I put it back.

== I think the joke is actually to be removed

I vote for keeping the joke. :)

integral of the arc

Hello, I'm trying to understand this theorem and everything I can follow except for why the integral of the arc is zero when a approaches infinity. Is there an explanation to this, or I'm missing something terribly simple?

Actually, I just found out the answer, and ironically, after hours and hours looking at the equations and the diagram, I found the answer by reading the joke. (The fact that the poles, if outside the curve makes the integral of the curve to be zero). So I hope that the joke stays as it greatly improved the understanding of at least 1 human being (me).

The joke that won't die... :) It wasn't clear to me either why the integral of the arc is zero, but having read this I have a clue. --Wtt 11:26, 2 May 2007 (UTC)

The joke won't answer this question. The question was not about the integral over the whole curve, but about the arc, where the article just states that it can be shown that the integral over the arc goes to zero. However, the reason for is is: a) the demoninator goes to zero like $1/a^{2}$, b) the numerator is bounded by 1, c) the arc length is proportional to $a$, thus the whole thing goes to zero as $a\rightarrow \infty$. I think something like this should really be included in the article, since this is one of the main point in applying the residue theorem (besides computing the residues, which is the other) (ezander) 134.169.77.186 (talk) 08:30, 14 September 2009 (UTC)

Indeed. I have detailed the proof concerning this point. For the detailed proof see Mathematical statistics: an introduction by Wiebe R. Pestman, appendix D, pag. 492. Mr Ape (talk) 15:38, 27 July 2010 (UTC)

The relevant pages are estimation lemma and Jordan's lemma, which should probably be merged. Tkuvho (talk) 09:00, 28 July 2010 (UTC)

Extremely Pointless joke

Please remove it, this doesn't suit the style. Please tell me what's the name of the Mathematical Journal. http://mathworld.wolfram.com/Pole.html scroll down.

• The jokes do not make the article any better, or easier to understand; even the source agrees that both jokes are "bad." I'm removing the "Humor" section, again. -ElTchanggo 05:41, 26 November 2006 (UTC)

• • And in addition, the second joke had been changed from the innocuous version at Mathworld, to a racist one. I agree to delete the humor section entirely. Spebudmak 05:53, 26 November 2006 (UTC)

Actual proof more powerful

The curve does need to be homotopic to a point in the set, but I do not believe a simply connected set is required. I'm still shaky on the idea of simply connected sets, but I'm pretty sure just one homotopic curve to a point is sufficient.49giantsharks (talk) 05:10, 2 May 2008 (UTC)

Notation

Why in the world are we using j to denote (one choice of) the square root of -1? The usual choice is i. Only under extreme duress have I ever seen j used in any math textbook or journal. — Preceding unsigned comment added by 173.228.89.128 (talk) 02:10, 2 November 2012 (UTC)

Non sequitur "one of the many things named after [Cauchy]"

I think it is a non sequitur statement, as well as an interruption of thought to have stated in the first line of the article: "one of many things named after Augustin-Louis Cauchy". I also think it does not improve nor clarify anything in the article. I would think, rather, that it should say something like "named for Augustin-Louis Cauchy," link to the page about him, and leave it at that. Someone coming to this page is not explicitly (I would bet not implicitly, either) looking for items named after Cauchy. I suggest someone change it, and, of course, am willing to be rebutted. DeftHand (talk) 08:50, 15 April 2013 (UTC)

Denominators

Emo7642 removed a factor of 2i from some denominators. That factor is actually correct: We have

${\frac {1}{2i}}\left({\frac {1}{z-i}}-{\frac {1}{z+i}}\right)={\frac {1}{2i}}\left({\frac {z+i}{z^{2}+1}}-{\frac {z-i}{z^{2}+1}}\right)={\frac {1}{2i}}\left({\frac {2i}{z^{2}+1}}\right)={\frac {1}{z^{2}+1}}.$

Thus I'll revert Emo7642's edit. Huon (talk) 21:17, 19 May 2014 (UTC)

Should define what a residue is

The article never explains how one finds the residue of a function at a pole Mameister (talk) 04:18, 30 September 2023 (UTC)