Al-Battani and Ibn al-Shatir, have which mutual occupation?
Al-Battani Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī (Arabic: محمد بن جابر بن سنان البتاني) (Latinized as Albategnius, Albategni or Albatenius) (c. 858 – 929) was an Arab astronomer, astrologer, and mathematician. He introduced a number of trigonometric relations, and his "Kitāb az-Zīj" was frequently quoted by many medieval astronomers, including Copernicus.
Al-Juwayni Imam al-Haramayn Dhia' ul-Din Abd al-Malik ibn Yusuf al-Juwayni al-Shafi'i (Persian: امام الحرمین ضیاءالدین عبدالملک ابن یوسف جوینی شافعی‎ ‎ , 17 February 1028— 19 August 1085; 419—478 AH) was a Persian Sunni Shafi'i jurist and mutakallim theologian. His name is commonly abbreviated as Al-Juwayni; he is also commonly referred to as Imam al Haramayn, meaning "leading master of the two holy cities", that is, Mecca and Medina.