Talk:Sharaf al-Din al-Tusi

message: I have removed the first sentence of the section Treatise on equations because it misrepresents the source cited.  More details can be found on an archive of the Mathematics in medieval Islam talk page.   An accurate account, written form a neutral point of view, of the various conjectures about how al-Din acquired his knowledge of the maxima of cubic polynomials should eventually be added to the article.
David Wilson (talk · cont) 14:00, 19 March 2011 (UTC)
thread_title:  Derivatives of cubic polynomials 

message: I removed, piecewise, several WP:COPYVIOs from this article (from ) before deciding that it was pretty well all made of that stuff. So I took it all out.
Besides which, the polynomial / derivative stuff was wrong, per what is now in  Mathematics in medieval Islam and the discussion there William M. Connolley (talk) 07:49, 27 April 2011 (UTC)
thread_title:  COPYVIOs 

message: The disputed claim that  al-Dīn_al-Ṭūsī discovered the derivative of cubic polynomials has just been re-added to the article by , with a citation to a source which is undoubtedly reliable, but which does not support the claim. I shall therefore be reverting the edit.  I refer the editor who made it to one of Wikipedia's guidelines which says you should only cite a source directly  if you have read that source yourself.  An account of what the cited source actually does say can be found  here.
David Wilson (talk · cont) 00:28, 11 June 2017 (UTC)
thread_title:  And again 

message: I reverted edits by user Wcherowi as his edits where unsourced and look like edit warring with anonymous user 37.172.49.217.
University of St Andrews is a reliable source and R. Rashed is also a reliable source about this topic and these two sources are cited in many good articles on Wikipedia. Please user Wcherowl, if you have different reliables sources claming something else, bring them on the talk page and do not remove sourced informations. — Preceding unsigned comment added by 2a01:e34:ee9d:a200:f039:9ff8:3983:5318 (talk) 11:57, September 3, 2017‎ (UTC)
:The two sources cited in the edits by the anonymous user from IP 37.172.49.217 were the University of St Andrews's MacTutor website, and an article, Innovation and Tradition in Sharaf al-Dīn al-Ṭūsī's Muʿādalāt, by J.L. Berggren in the Journal of the American Oriental Society. However, some key claims made in the material added by these edits are egregious misrepresentations of these sources, and simply not supported by either of them.  To wit:
:* "He also developed the concepts of a derivative function … ".  This is cited to the Mactutor article, but nothing remotely like that is stated anywhere in that article.  What it actually says is:
:::"Basically using the derivative of this expression, al-Tusi finds [where] the maximum occurs …
:::"Of course al-Tusi's use of the derivative of a function, without of course saying so, is very interesting. The paper [11] attempts to discover the origin of this implicit use of the derivative, which the author claims arises from algebraic proofs based on analytical procedures. The paper [12] suggests that a rather different approach, not one analogous to the modern derivative, lay behind Al-Tusi's method. The papers [10] and [14] contribute to this discussion; see also [2], [3] and [4] for further insights.
::Moreover, Berggren's article actually contradicts the notion that even an implicit use of derivatives in al-Tusi's work can be considered an established fact.
:* "He understood the importance of the discriminant of the cubic equation to find algebraic solutions to certain types of cubic equations."  This is cited to Berggren's article, which nowhere uses the term "discriminant" for any purpose, let alone as the name of something which al-Tusi supposedly recognised the "importance" of.  The Mactutor article does use the term "discriminant" once:
:::"Then Al-Tusi deduces that the equation has a positive root if
:::where D is the discriminant of the equation."
::but nowhere says anything about al-Tusi "understanding" its "importance". In fact, the statement in the MacTutor article is a little misleading, in that al-Tusi never expressed inequalities in forms like A – B ≥ 0.  Since he didn't recognise that an expression of the form A – B made any sense if A < B, he never rewrites inequalities such as A ≥ B or A ≤ B in the forms A – B ≥ 0 and A – B ≤ 0 which we recognise today as being equivalent.
:Your reversions of user Wcherowi's edits were therefore completely unwarranted.
:David Wilson (talk · cont) 08:46, 4 September 2017 (UTC)
replies: text: Your comments are a little out of date. The article has been changed (before you wrote this, but maybe a tie time-wise) in what I think is a positive way. Wikaviani and my edits have never been removed from the article, but there is some difficulty with looking at earlier versions of the page at the moment (I hope that this gets fixed). --Bill Cherowitzo  (talk) 22:30, 5 September 2017 (UTC)
replies: text:  I'd say mentioning algebraic geometry is justified, but I'm not sure about "founder of". Perhaps this quote might be useful. Wiqi(55) 22:44, 5 September 2017 (UTC)

text: If it is the wrong al-Tusi then by all means remove the sentence. I reverted your change for two reasons. First of all the St. Andrews citation is not an independent source since all they are doing is citing Rashed's comment. That article had already been cited three times and there was no need for a fourth reference to it. Rashed's comment seems to me to be a bit of hype (or perhaps just how others are using his comments) and I would like to see some independent source also make this claim before reinstating it. --Bill Cherowitzo  (talk) 01:49, 6 September 2017 (UTC)
thread_title:  Edit warring and removal of sourced materials