while astronomy assimilated Hellenic ideas to some extent mathematics was really innovative. Indian astronomers were able mathematicians too. The doyen among them, Aryabhatta I (b.476 A.D.) gave the value of pi (3.1416 approx., a value used even today) worked out trigonometrical tables, areas of triangles and other plane figures, arithmetical progression, summation of series, indeterminate equations of the first order and the like. He expounded that the earth rotates about its own axis and the period of one sidereal rotation given by him is equivalent to 23h 56m 4s.1, while the modern value is 23h 56m 4s.091. He discarded the mythical Rahu-Ketu postulate concerning eclipses in favour of a scientific explanation.
Aryabhatta’s junior contemporary Varahamihira, was well known for his compendium, the Panchasiddhantika, a compilation of the then extant five astronomical works called the Siddhantha- Surya, Paulisha, Romaka, Vasishta, and Paitamaha. Of them, the Suryasiddhanta, which he regarded as the most accurate, underwent revisions from time to time and continues to be an important text for computing pancangas.
Brahmagupta was a noted astronomer mathematician of the 7th Century. His remarkable contribution was his equation for solving indeterminate equations of the second order – an equation that appeared in Europe a thousand years later known as Pell’s equation. His lemmas in this connection were rediscovered by Euler (1764) and Lagrange (1768). Brahmagupta was also the first to enunciate a formula for the area of a rational cyclic quadrilateral. In the latter half of the first millenium A.D. there were other noted astronomers and mathematicians like Bhaskara I, Lalla, Pruthudakasvamin, Vateshvara, Munjala, Mahavira