born , Dec. 1, 1792, Nizhny Novgorod, Russia
died Feb. 24, 1856, Kazan
Russian mathematician.
His entire life centred around the University of Kazan, where he studied and later (from 1816) taught. In 1829 he published his groundbreaking theory, a geometry that rejected Euclid 's parallel postulate . It was the final solution to a problem that had baffled mathematicians for 2,000 years. Lobachevsky also did distinguished work in the theory of infinite series, especially trigonometric series, as well as in integral calculus , algebra , and non-Euclidean geometry .