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.
Al-Hasan ibn Sahl Al-Hasan ibn Sahl (died 850/51) was an Abbasid official and governor of Iraq for Caliph al-Ma'mun (reigned 813–833) during the Fourth Fitna.