The exact formula for π was first given as an INFINITE SERIES by which Indian mathematician (14th century)?

Madhava of Sangamagrama (14th century Kerala) gave the first infinite-series formula for π: π = 4 − 4/3 + 4/5 − 4/7 + 4/9 − … (the 'Madhava–Leibniz series'). The European discovery of this series by Leibniz came about 300 years later. The series approaches π more closely as more terms are added — but since π is irrational, the sum never terminates.