Cadambathur Tiruvenkatacharlu Rajagopal
Cadambur Tiruvenkatachari Rajagopal (8 September 1903 – 25 April 1978) was an Indian mathematician from Madras. He was the eldest son of Tiruvenkatachari and Padmammal and had two younger brothers, C.T. Venugopal and C. T. K. Chari, and a sister named Kamala.
Rajagopal studied at Presidency College and earned an honours degree in mathematics in 1925. He worked in clerical service for a while, then taught mathematics at Annamalai University. From 1931 to 1951 he taught at Madras Christian College.
In 1951 he joined the Ramanujan Institute for Advanced Study in Mathematics. He and Vaniyambadi Rajagopala Srinivasaraghavan wrote An Introduction to Analytical Conics, a textbook published in 1955 by Oxford University Press in India. The book was praised for its clear discussion and its many historical references.
Rajagopal became director of the Ramanujan Institute in 1955 and helped it become India’s leading mathematics research center. In 1967 the Institute merged with the Department of Mathematics at the University of Madras.
His research covered sequences, series, summability, and he published more than 80 papers. He is best known for work that generalised and unified Tauberian theorems, and he also studied the history of medieval Indian mathematics. He showed that the series for arctan x (discovered by James Gregory) and for sin x and cos x (discovered by Isaac Newton) were known to Hindu mathematicians about 150 years earlier, recognizing Madhava as the first to discover these series.
This page was last edited on 3 February 2026, at 14:06 (CET).