Bhaskara II

Bhaskara II, also known as Bhaskaracharya, meaning Bhaskara the Teacher, (1114-1185 CE) was an Indian mathematician and astronomer who led the astronomical observatory at Ujjain. His major work, the Siddhanta Shiromani, is organized into four parts covering arithmetic, algebra, mathematics of the celestial sphere and astronomy of the planets, and includes a rigorous demonstration of the Pythagorean theorem and early work on indeterminate equations and permutations and combinations. Some of his results, including calculations involving infinitesimally small quantities and an early form of what would later be formalized in Europe as Rolle's theorem in calculus, are cited by some historians of mathematics as anticipating concepts of differential calculus centuries before Newton and Leibniz, though the extent of that anticipation is debated among specialists. His arithmetic textbook Lilavati remained a standard mathematics text in India for centuries after his death.