Pierre de Fermat

Pierre de Fermat (1601-65), French mathematician, born in Beaumont-de-Lomagne. In his youth, with his friend the French scientist and philosopher Blaise Pascal, he made a series of investigations into the properties of figurate numbers. From these studies Fermat later derived an important method of calculating probabilities. He was also greatly interested in the theory of numbers and made several discoveries in this field. For these contributions some consider him the father of the modern theory. He anticipated differential calculus with his method of finding the greatest and least ordinates of curved lines. See Fermat's Last Theorem.