Talk:Guillaume de l'Hôpital

Untitled
the brachistochrone page says johann bernoulli solved the curve first?

What did he die of
What did L'Hopital die of?

my theory, he was rolled for his money Duel me 12:51, 4 July 2006 (UTC)

Spelling: French version
From the French Wikipedia version of this article:

Son nom s'écrit aussi L'Hospital. Contrairement à ce qu'on pourrait croire, l'accent circonflexe n'est pas un anachronisme : si son livre ne comporte pas de nom d'auteur, son ami Varignon, dans les compléments qu'il publia au livre (1725), écrit toujours son nom avec l'accent circonflexe, et dans l'encyclopédie de D'Alembert-Diderot, c'est « L'Hopital » qu'on trouve, sans accent ni s.

My translation: His name is also written as "l'Hospital." Contrary to what one might think, the circumflex accent is not an anachronism: even though his book did not carry his name, his friend Varignon, in the supplements that he published for the book (1725), always wrote his name with the circumflex accent, and in the encyclopedia of D'Alembert-Diderot, it is "L'Hopital" that one finds, without either the accent or the s.

What is the truth about the spelling of his name and the origin of the differing versions?
 * the current description in the (english) article is correct (he spelled himself with a (silent) s, but the french spelling rules have changed since his time).--84.174.207.73 (talk) 21:53, 7 January 2009 (UTC)

I have another question, is the 'l' supposed to be capitalized or lowercase? That is, l'Hôpital (l'Hospital) or L'Hôpital (L'Hospital)? From frwiki they seem to always capitalize it while on enwiki it's only capitalized if it's in the beginning of the sentence, and lowercase otherwise. Nguyên Lê (talk) 12:34, 15 August 2022 (UTC)

What is this comment at the end of the article?
I totally don't understand what this person talks about.

1. It is wrong. If you don't require the numerator to converge at all, then what about cos x/x when x -> infinity? The limit is of course 0, but you gent divergent function if you differentiate both the numerator and the denominator.

2. It is out of place in the formatting. It looks like it mean to be some kind of talk, but it is in the main page, below "See also".

3. Any detailed description of the theorem should go the page of L'Hôpital's rule.

If there is no reaction to this, I'll remove that edit.

--Csab (talk) 15:18, 7 January 2008 (UTC)

Pronunciation
Speaking of which, can we get French and Anglicized pronunciations of his name in the article? I'd do it myself if I only had a clue. -- /ˈwɪki waʊ/.  02:48, 19 October 2009 (UTC)

what sort of calculus?
L'Hopital clearly states on page xii that what we are dealing with is Leibniz's calculus, which he refers to as calcul differentiel. Leibniz's calculus is what we call today infinitesimal calculus. Perusing the first eleven pages preceding page xii one notices that L'Hopital never stops talking about the infiniment petits, the French term for infinitesimals (Cauchy also preferred this term, while Carnot spoke of infinitesimals). A quick perusal of our differential calculus page reveals that it deals with nothing of the sort; of course, L'Hopital's calculus was not "rigorous", while what we call today "differential calculus", is. Both the name and the content of infinitesimal calculus are a more appropriate link for the subject matter of L'Hopital's book. Tkuvho (talk) 06:41, 20 July 2010 (UTC)
 * Wrong. "What l'Hopital clearly states on page xii" is :
 * "Dans tout cela il n'y a encore que la première partie du calcul de M. Leibniz, laquelle consiste à descendre des grandeurs entières à leurs différences infiniment petites, et à comparer entre eux ces infiniment petits de quelque genre qu'ils soient : c'est ce qu'on appelle Calcul différentiel. Pour l'autre partie, qu'on appelle Calcul intégral, [...] M. Leibniz m'ayant écrit qu'il y travaillait [...], je n'ai eu garde de priver le public d'un si bel Ouvrage."
 * In other words (French is my native language) l'Hospital writes that Leibniz calculus consists of two parts, which he calls differential and integral calculus (and by his (old-fashioned) description of both these two parts, they are exactly what is still called differential calculus and integral calculus today). Hence what he calls Leibniz calculus is not differential calculus, but infinitesimal calculus. Anyway, neither of these two expressions have to be mentionned here, and only the expression differential calculus has to be mentionned when talking about l'Hospital's book, since he explicitely names it so and annouces that he restricts to this first part (because Leibniz intends to publish about the second one). I give up (I have enough work on french WP), and I leave to other contributors on english WP the task of restablishing a correct version, here and on l'Analyse des Infiniment Petits pour l'Intelligence des Lignes Courbes (and maybe elsewhere). Anne Bauval (talk) 15:23, 20 July 2010 (UTC)
 * Your message is unnecessarily agitated. I don't think we disagree about the facts.  L'Hopital indeed used the expression "differential calculus".  The sense in which he used this expression is what we describe today by the historical term "infinitesimal calculus" (as opposed to its common meaning as "the calculus", which is a kind of a dead metaphor, frequently used in course titles).  The term "differential calculus" the way we use it today is different from L'Hopital's sense.  Namely, we use it to describe the post-Weierstrassian formalisation of the calculus.  L'Hopital certainly did not have this in mind when he employed the term.  This is why I think it would be misleading to use the term on this page.  I see that you disagree and that's perfectly legitimate.  Good luck on French wiki.  Tkuvho (talk) 16:44, 20 July 2010 (UTC)


 * P.S. You wrote "two parts, which he calls differential and integral calculus (and by his (old-fashioned) description of both these two parts, they are exactly what is still called differential calculus and integral calculus today)." This would appear to be a historical inaccuracy:  I can't see how you can claim that "they are exactly what is still called, etc".  Tkuvho (talk) 16:48, 20 July 2010 (UTC)
 * In response to your WPM comment: insisting on historical accuracy is not POV pushing, on the contrary. Tkuvho (talk) 18:24, 20 July 2010 (UTC)
 * MacTutor calls it a treatise on differential calculus. I'd say go with that unless someone has another source that says otherwise. If then is still some doubt then why not simply say calculus and avoid the issue all together?--RDBury (talk) 23:52, 20 July 2010 (UTC)

Quality assessment
This article appears to have been very poorly written and contains little besides repeated assertions about l'Hôpital's rule. I've spent quite a bit of time tidying it up, but, frankly, it would have been better just to rewrite it from scratch using a reputable source. In any case, issues of proper target to link calculus seem infinitesimal compared to the Gargantuan task of creating a reasonable biographical article. Arcfrk (talk) 05:17, 21 July 2010 (UTC)


 * Updated. Arcfrk (talk) 08:50, 21 July 2010 (UTC)
 * Good job! Tkuvho (talk) 11:50, 21 July 2010 (UTC)
 * As per your edit title: I am just curious: which McT "blooper" did you correct? Tkuvho (talk) 14:04, 22 July 2010 (UTC)
 * The claim that his father was Duc d'Orléans: that seemed a bit too far-fetched to be true when I first put it in, but I forgot to double-check. The name of the l'Hôpital's estate, Oucques, is misspelt there, too. By the way, here is an article about l'Hôpital written by Abraham Robinson. I haven't used it in writing my revision, but do you think it should be added as a reference? Arcfrk (talk) 01:19, 23 July 2010 (UTC)
 * Thanks for the link, I did not know about it. It has valuable information about the book "Analyse etc".  Some of it should be added at the wiki page for the book.  Note that Robinson spells the title without the definite article.  The second edition, which is online, spells it the same way.  Later editions added the definite article, as in "l'analyse".  Has anyone seen the first edition?  There seems to be a systematic error in the literature (one historian copying from the earlier one) in citing the title with the definite article.  Unless, of course, the first edition also had the l'. Tkuvho (talk) 03:48, 23 July 2010 (UTC)
 * You are correct about the book's title, good catch! And I see that you have already corrected the title of the article about the book by removing the article from the title of the article which is the title of the book (ugh!) [[Image:smiley.svg ||15px]] Arcfrk (talk) 06:42, 23 July 2010 (UTC)
 * Thanks. It would be good for someone to get around to adding the information from the Dictionary of scientific biography to the book page.  Also, the controversy involving l'H and Bernoulli is reported in contradictory ways on the two biography pages.  Should the whole thing be moved to the book page? Tkuvho (talk) 11:49, 23 July 2010 (UTC)
 * I think that some description of the controversy is warranted at both bio pages. "Signed a contract" (at Bernoulli page) is misleading, but the short paragraph there is easy enough to fix (and I scratched my head trying to understand how "L'Hôpital controversy" is a part of his "Scientific contribution" &mdash; one might think that besides quarreling with l'Hôpital, he accomplished little else). Arcfrk (talk) 17:07, 23 July 2010 (UTC)

Spelling, revisited
Since he himself wrote his name with an s, I personally believe that the article should be titled "Guillaume de l'Hospital". Johncolton (talk) 21:26, 10 January 2014 (UTC)\
 * You are right. The cap over the 'o' represents that it used to be spelled as 'os' at some point.

A lot of citations needed
There are a number of uncited claims in the Calculus Textbook section (basically all of it is uncited). I have added "Citation needed" markers in the last two sentences of that section because I think that those claims are basically undisprovable. Rest is factual, but does not lead to a source of any sort. This section, if cleaned up and referenced, would present a breve but clear account of the chronology of l'Hopital's books. — Preceding unsigned comment added by 128.178.125.49 (talk) 13:56, 24 February 2014 (UTC)

Quality of portrait
The quality of the portrait in this article is not up to the standards of Wikipedia. It is grainy, low resolution, and has evidence of severe compression. — Preceding unsigned comment added by 96.228.248.198 (talk) 21:54, 8 January 2016 (UTC)