Jean le rond d'Alembert et les sciences (anglais)

« JEAN LE ROND D'ALEMBERT > Was born the November, 16th of 1717 in Paris (yesterday, it was the tercentennial of his birth), and died in 1783 à Paris > Mathematician > Physician > Philosophe > Encyclopaedist > known for: - The encyclopaedia (that he directed with Diderot) - His mathematical works - His Physical works I/ CHILDHOOD > Son of the writer Claudine Guérin de Tencin and the duke of Aremberg (he used this name in order to get into the university, but he changed it by D'Alembert) > He was abandoned by his mother in the S t Jean-Le-Rond Chapel, placed side by side to the Paris's cathedral.

D'Alembert owes this chapel his name, according to the custom. > Discreetly grown by the knight Louis-Camille Destouches the trustworthy man of the duke. II/ STUDIES > Baccalaureate in arts at the collège des Quatre Nations > became a lawyer in 1738 > Then, studies of medicine > Then, studies of mathematics. III/ MATHEMATICAL WORKS 1.

THE FUNDAMENTAL THEORM OF ALGEBRA > In French, we say that is the D’Alembert or the D’Alembert-Gauss theorem.

> This theorem say that every non-constant single-variable polynomial with n complex coefficients has exactly n complex roots (but not necessarily distinct). > This theorem was firstly enounced by D’Alembert in this book le Traité de Dynamique , but was proven by Gauss, who also pointed out an error in the D’Alembert reasoning. 2.

THE D'ALMEBERT RATIO TEST > That is a test or a "criterion" for the convergence of a series > Let be a series with strictly positive terms which the ratio tend towards a limit L 0.

Then:. »