Demoivre, ABRAHAM

Demoivre, ABRAHAM, a distinguished mathematician, was born at Vitry, in Champagne, 26th May 1667. A Protestant, he fled to England in 1688, after the revocation of the Edict of Nantes, and there long supported himself by private tuition and public lecturing. The appearance of Newton's Principia incited him to increased devotion to mathematical studies, and at last he ranked among the leading mathematicians of his time. He was a member of the Royal Society of London, and of the Academies of Berlin and Paris. The Philosophical Transactions of London are enriched by many contributions from his pen; and he was so esteemed by the Royal Society that they judged him a fit person to assist in the decision of the famous contest between Newton and Leibnitz for the merit of the invention of fluxions. He died in London, 27th November 1754. Among his published works are Annuities upon Lives (1725), Miscellanea Analytica de Seriebus et Quadraturis (1730); and The Doctrine of Chances (1718 and 1738), dedicated to Sir Isaac Newton. Demoivre's name is well known from its association with a useful trigonometrical formula—viz. that, where $k$ is any real quantity, $\backslash cos\; k\backslash theta\; +\; i\; \backslash sin\; k\backslash theta$ is always one value of $(\backslash cos\; \backslash theta\; +\; i\; \backslash sin\; \backslash theta)^k$.