Brahmagupta was a distinguished 7th century mathematician and astronomer from India. He lived and worked in Ujjain, where he wrote his first book Brahmasphuta-siddhanta at the age of 30. In his works, he introduced concepts like zero, negative numbers, and algorithms for solving quadratic equations that are similar to the quadratic formula. He made contributions to arithmetic, geometry, and algebra, including formulas for the areas of triangles, volumes, and geometric progressions. Brahmagupta was a pioneer in applying algebra to astronomy.