835-912 Arab mathematician who wrote works on ratio, proportion, and arcs. Born in Baghdad and raised in Damascus, Ahmed spent much of his career in Egypt, where he served as private secretary to the powerful ruler Ahmad ibn Tulun. His book on ratio,...

Ahmed ibn Yusuf ibn Ibrahim ibn Tammam al-siddiq Al-Baghdadi also known as Abu Ja'far Ahmad ibn Yusuf and Ahmed ibn Yusuf al-misri (835 - 912) was an Arab mathematician, like his father Yusuf ibn Ibrahim (Arabic يوسف بن ابراهيم...