Joseph-Louis Lagrange

Joseph-Louis Lagrange (1736 to 1813), born Giuseppe Luigi Lagrangia, was an Italian and naturalized French mathematician, physicist and astronomer who made significant contributions to analysis, number theory and both classical and celestial mechanics. In calculus he developed a novel approach to interpolation and Taylor's theorem, and three papers of 1783, 1792 and 1793 on the method of interpolation left the part of finite differences that deals with it in the stage in which he left it. He also devised a system of calculating planetary perturbations by means of mechanical quadratures that formed the basis of most later work. In 1766 he succeeded Euler as director of mathematics at the Prussian Academy of Sciences in Berlin, in 1787 he moved to Paris and joined the French Academy of Sciences, and in 1794 he became the first professor of analysis at the Ecole Polytechnique.