Fermat

Pierre de Fermat (; French:; 17 August 1601 – 12 January 1665) was a French magistrate, polymath, and mathematician credited for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous to that of differential calculus, then unknown, and his research into number theory. He made notable contributions to analytic geometry, probability, and optics. […]

Text: Wikipédia, CC BY-SA 4.0, excerpt · Portrait: Rolland Lefebvre, Public domain