Sharafeddin Muzzafar-i Tusi, was a Persian mathematician of the middle ages, (1135 - 1213).

Tusi taught various mathematical topics including the science of numbers, astronomical tables and astrology, in Aleppo and Mosul. His best pupil was Kamal al-Din ibn Yunus. In turn Kamal al-Din ibn Yunus went on to teach Nasir al-Din al-Tusi, one of the most famous of all the Islamic scholars of the period. By this time Tusi seems to have acquired an outstanding reputation as a teacher of mathematics for some travelled long distances hoping to become his students.

Tusi wrote some treatises on algebra. There, he went on to give what we would essentially call the Ruffini-Horner method for approximating the root of the cubic equation. Although this method had been used by earlier Arabic mathematicians to find approximations for the nth root of an integer, Tusi is the first that we know who applied the method to solve general equations of this type.

Another famous work by Tusi is one in which he describes the linear astrolabe, sometimes called the "staff of al-Tusi", which he invented.

See also

• List of Iranian scientists

External link

• His bio at The St Andrew's School of Mathematics, Scotland website