Kūshyār ibn Labban's main work was probably done about the beginning of the 11th century, and seems to have taken an important part in the elaboration of trigonometry. He continued the investigations of the 10th century mathematician and astronomer Abul Wáfa, and devoted much space to this in his zīj (book of astronomical 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.[3] The tables were translated into the Persian language before the end of the century. He wrote also an astrological introduction and an arithmetic treatise Principles of Hindu Reckoning (Kitab fi usul hisab al-hind), that is extant in both Arabic and Hebrew), and was translated to English in 1963.[4]
Kūshyār Daylami's pupils included the Persian mathematician Ali ibn Ahmad al-Nasawi. Kūshyār ibn Labban is thought to have died in Baghdad.
References
^Hockey, Thomas (2014). Biographical encyclopedia of astronomers. New York: Springer. p. 1074. ISBN9781441999184. Kushyar ibn Labban was an eminent Iranian astronomer known for his work on astronomical handbooks (zijes) in addition to his work in mathematics and astrology.
^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.