BRAHMAGUPTA

born 598 died c. 665, , India the last and most accomplished of the ancient Indian astronomers, who set forth the Hindu astronomical system in verse form in the Brahma-sphuta-siddhanta (628; The Opening of the Universe). Two chapters are devoted to mathematics, including an arithmetical progression, a quadratic equation, and proofs of various geometrical theorems on the right-angled triangle, on areas of triangles and quadrilaterals, and on surfaces and volumes. The other 23 chapters are concerned with astronomy and deal with lunar eclipses, solar eclipses, planetary conjunctions, the lunar phases, and the determination of the positions of the planets.