In the Greek/Indian period, it is noticeable that different radii were used in connection with the chord. This manner continued in the Indian period with the sine, i.e. different sine tables existed. But throughout the Arabic-Islamic period, there was stability in the radius (for the sine). At the time of al-Battani new terms were introduced, not as functions of angles but as lengths, and again different tables for the same term. Here these terms were not bounded to the circle, and the term miqyas r (measure), which was variable, was used to express the radius related to these terms. The trigonometric functions at that time were treated as if they were two different groups. While at Abu al-Wafa''s time, there was an advancement by introducing the new terms as functions of angles, and they were immediately bounded to the circle, and instead of having two circles in the same figure, a kind of unity appeared, and again there was stability in the value of r, and therefore only one table for each function, and thus the new functions started to appear more abstract than practical as the sine did before, and this unity remained fixed in the modern times.
...More
Article
Moussa, Ali;
(2011)
Mathematical Methods in Abu Al-Wafa's Almagest and the Qibla Determinations
(/isis/citation/CBB001033814/)
Article
Kennedy, Edward S.;
(2009)
Al-Battānī's Astrological History of the Prophet and the Early Caliphate
(/isis/citation/CBB001023951/)
Book
Jacques Sesiano;
(2017)
Magic Squares in the Tenth Century: Two Arabic Treatises by Anṭākī and Būzjānī
(/isis/citation/CBB096340211/)
Article
Raynaud, Dominique;
(2012)
Abu Al-Wafa' Latinus? A Study of Method
(/isis/citation/CBB001036230/)
Article
McCarthy, Daniel P.;
Byrne, John G.;
(2003)
Al-Khwārizmī's Sine Tables and a Western Table with the Hindu Norm of R = 150
(/isis/citation/CBB000340513/)
Essay Review
Michel, Alain;
(2003)
Géométrie et philosophie: De Thābit ibn Qurra à ibn al-Haytham
(/isis/citation/CBB000340511/)
Chapter
Terence J. Kleven;
(2012)
Al-Fārābī's Five Aphorisms on Logic
(/isis/citation/CBB764051773/)
Article
Paris, Harry S.;
Amar, Zohar;
Lev, Efraim;
(2012)
Medieval History of the Duda'im Melon (Cucumis melo, Cucurbitaceae)
(/isis/citation/CBB001320676/)
Article
Yücesoy, Hayrettín;
(2009)
Translation as Self-Consciousness: Ancient Sciences, Antediluvian Wisdom, and the `Abbasid Translation Movement
(/isis/citation/CBB001030427/)
Book
Rashed, Roshdi;
(2002)
Les mathématiques infinitésimales du IXe au XIe siècle
(/isis/citation/CBB000201520/)
Chapter
de Blois, François;
(2014)
Some Early Islamic and Christian Sources Regarding the Jewish Calendar (9th--11th Centuries)
(/isis/citation/CBB001213978/)
Chapter
Abattouy, Mohammed;
(2002)
The Aristotelian Foundations of Arabic Mechanics: From the Ninth to the Twelfth Century
(/isis/citation/CBB000301298/)
Article
Ricordel, Joëlle;
(2008)
De Salerne à Al-Andalus: l'empreinte des médecins de Kairouan
(/isis/citation/CBB000933394/)
Article
Sarhangi, Reza;
(2008)
Illustrating Abu al-Wafā' Būzjānī: Flat Images, Spherical Constructions
(/isis/citation/CBB001031123/)
Article
Brummelen, Glen Van;
Mimura, Taro;
Kerai, Yousuf;
(2012)
Al-Samaw'al's Curious Approach to Trigonometry
(/isis/citation/CBB001421116/)
Book
J.L. Berggren;
(2016)
Episodes in the Mathematics of Medieval Islam
(/isis/citation/CBB283154466/)
Book
Brummelen, Glen Van;
(2009)
The Mathematics of the Heavens and the Earth: The Early History of Trigonometry
(/isis/citation/CBB000950326/)
Article
Rashed, Roshdi;
(2010)
Les constructions géométriques entre géométrie et algèbre: L'Épître d'Abū al-Jūd à al-Bīrūnī
(/isis/citation/CBB000933050/)
Book
Rashed, Roshdi;
(2000)
Les mathématiques infinitésimales du IXe au XIe siècle: théorie des coniques, constructions géométriques et géométrie pratique. Vol. 3: Ibn al-Haytham
(/isis/citation/CBB000774771/)
Chapter
Boulahia, Néjib;
(2007)
Quelques contributions arabes en trigonométrie sphérique
(/isis/citation/CBB001024046/)
Be the first to comment!