YaÊ¿qÅ«b ibn ṬÄriq
Yaqub ibn Tariq (Arabic يعقوب بن طارق, DMG Ya ʿ qūb b. Tariq ) was a Persian astronomer and mathematician of the 8th century.
He lived in Baghdad and was considered one of the greatest astronomers of his time. He worked at the court of al - Mansur, on whose behalf he ( called Siddhanta, Sanskrit for textbook, probably from the textual tradition of Brahmagupta ) to 770 Indian astronomical texts translated into Arabic, along with Muhammad al- Fazari. Like al - Fazari he wrote it based an astronomical manual ( Zij ), which is only fragmentarily known. They had been brought by an Indian named Kankah to Baghdad. They also used Persian and Greek sources and laid back then bases the development of astronomy in the Islamic world.
He also wrote a book on cosmography of the Indians ( Tarkīb al - Aflak ) and a treatise Kitab al'ilal in which he sought to justify the astronomical calculation rules mathematically. Of these treatises, however, is only fragmentary something known by the mentions in Al -Biruni, and partly follows from the fact that Tariq has as well as his colleague al - Fazari not understood everything correctly in the Indian texts.