Kushyar ibn Labban

Abul-Hasan Kūshyār ibn Labbān ibn Bashahri Gilani (971 - 1029), also known as Kūshyār Gīlānī (PerB|کوشیار گیلانی), was a Persian mathematician, geographer, and astronomer from "Jilan", a.k.a. Gilan, south of the Caspian Sea, Iran.

His main work was probably done about the beginning of the eleventh century, and seems to have taken an important part in the elaboration of trigonometry. For example, he continued the investigations of Abul Wáfa, and devoted much space to this in his zij (or collection of tables) "az-Zīj al-Jamī wal-Baligh" ("the comprehensive and mature tables"), which incorporated the improved values of the planetary apogees observed by al-Battani. [E. S. Kennedy, "A Survey of Islamic Astronomical Tables," (Transactions of the American Philosophical Society, New Series, 46, 2), Philadelphia, 1956, pp. 3, 34-5.] The tables were translated into Persian before the end of the century. He wrote also an astrological introduction and an arithmetic treatise (extant in Hebrew).

He was the teacher of Ahmad Nasawi. He is thought to have died in Baghdad.

Notes

ources

* H. Suter: Mathematiker und Astronomen der Araber (83, 235, 1900; 168, 1902).
* M Levey and M Petruck (trs.), Kushyar ibn Labban, Principles of Hindu reckoning (Madison, 1965).

ee also

*List of Iranian scientists
*zij

External links

* [http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Kushyar.html Laban's Bio from St Andrew's School of Mathematics website, Scotland.]