Brahmagupta was an Indian mathematician and astronomer who is credited as the first person to understand and formalize the concept of the number zero for nothing in mathematics. He is the author of two early works on mathematics and astronomy: the Brāhmasphuṭasiddhānta, a theoretical treatise, and the Khandakhadyaka, a more practical text. He is also credited with the first clear description of the quadratic formula in his main work, the Brāhma-sphuṭa-siddhānta. 598 – 665; died at about 67. Alive at the same time as Muhammad, Umar ibn Al-Khattāb, Pseudo-Dionysius the Areopagite, Alī ibn Abī Ṭālib, and Abu Bakr. Wiki link