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Brahmagupta primarily worked in the 7th century, a period of significant mathematical and astronomical advancements. Born in 598 CE in Ujjain, India, he made notable contributions to the fields of arithmetic, algebra, and trigonometry. His most famous work, the Brahmasphutasiddhanta, is a comprehensive treatise that includes solutions to quadratic equations, the use of zero as a placeholder, and the development of trigonometric formulas.