Who covered the most disciplines, Abū Sahl al-Qūhī or Al-Farabi?
Abū Sahl al-Qūhī Abū Sahl Wayjan ibn Rustam al-Qūhī (al-Kūhī ; Persian: ابوسهل بیژن کوهی‎ ‎ "Abusahl Bijan-e Koohi") was a Persian mathematician, physicist and astronomer. He was from Kuh (or Quh), an area in Tabaristan, Amol, and flourished in Baghdad in the 10th century. He is considered one of the greatest Muslim geometers, with many mathematical and astronomical writings ascribed to him.
Istakhri Abu Ishaq Ibrahim ibn Muhammad al-Farisi al Istakhri (also known as Estakhri, Persian: استخری‎ ‎ , i.e. from the Iranian city of Estakhr, b. - d. 957 AD [346AH]) was a Persian medieval geographer in medieval Islam and traveler of the 10th century.