François Budan de Boislaurent

Ferdinand François Désiré Budan de Boislaurent was a French amateur mathematician, born in Limonade, Cap-Français, Saint-Domingue, now Haiti, on 28 September 1761, best known for a tract, Nouvelle méthode pour la résolution des équations numériques, first published in Paris in 1807 but based on work from 1803. He studied medicine in Paris and received a doctorate for a thesis on whether a patient should be informed of his situation. His method obtains the coefficients of a shifted polynomial through a Pascal-like triangle, and combined with Descartes' Rule of Signs it yields an upper bound on the number of real roots of a polynomial inside an open interval; this result, Budan's Theorem, tended to be eclipsed by an equivalent result due to Joseph Fourier after a priority dispute. He died in Paris on 6 October 1840.