Virasena

Acharya Virasena (792-853 CE), also known as Veerasena, was a Digambara monk and belonged to the lineage of Acharya Kundakunda. He was an Indian mathematician and Jain philosopher and scholar. He was also known as a famous orator and an accomplished poet. His most reputed work is the Jain treatise Dhavala. The late Dr. Hiralal Jain places the completion of this treatise in 816 AD.

Virasena was a noted mathematician. He gave the derivation of the volume of a frustum by a sort of infinite procedure. He worked with the concept of ardhachheda: the number of times a number can be divided by 2. This coincides with the binary logarithm when applied to powers of two, but gives the 2-adic order rather than the logarithm for other integers.

Virasena gave the approximate formula C = 3d + (16d+16)/113 to relate the circumference of a circle, C, to its diameter, d. For large values of d, this gives the approximation π ≈ 355/113 = 3.14159292..., which is more accurate than the approximation π ≈ 3.1416 given by Aryabhata in the Aryabhatiya.

Life
Virasena was proficient in astrology, grammar, logic, mathematics and prosody. He wrote Dhavala, a commentary on Jain canon Shatakhandagama. He also started the work on Jayadhavalaa which was completed by his disciples. He was among the jewels of Rashtrakuta king Amoghavarsha.

His lineage started with Chandrasena who initiated Aryanandi. Aryanandi initiated Virasena and Jayasena. Virasena initiated six disciples who were Dasharayguru, Jinasena, Vinayasena, Shripal, Padmasena and Devasena. Dasharayguru and Jinasena initiated Gunabhadra who later initiated Lokasena. Vinayasena initiated Kumarasena who started the Kashtha Sangha.