Use of hypotenuse in the computation of the equation of the centre under the epicyclic theory in the school of Āryabhaṭa I???

Abstract

The present paper refutes the assertion of T. S. Kuppanna Shastri that the use of the hypotenuse in the computation of the equation of the centre under the epicyclic theory is one of the principal characteristics of the school of Āryabhaṭa I. It has been shown that the followers of Āryabhaṭa I, like other Hindu astronomers, did not employ the hypotenuse in calculating the equation of the centre under the epicyclic theory. The reason for not using the hypotenuse is explained and the views of the prominent Hindu astronomers, such as Bhāskara I, Govinda Svāmi, Parameśvara, Nīlakaṇṭha, and others are cited in support.