Brahmagupta

Brahmagupta (598-668 CE) was an Indian mathematician and astronomer who led the astronomical observatory at Ujjain, one of the leading centers of mathematical science in early medieval India. His treatise the Brahmasphutasiddhanta gave the first known systematic rules for arithmetic operations using zero as a number in its own right, including rules for treating it in addition, subtraction and multiplication, and set out a general solution to quadratic equations and a formula for the area of a cyclic quadrilateral now known as Brahmagupta's formula. His works were later translated into Arabic and helped transmit Indian numerals and mathematical methods into the wider Islamic and, eventually, European mathematical tradition. He also wrote extensively on astronomy, including methods for calculating eclipses and planetary positions.