Les équations différentielles ont 350 ans. (The differential equations are 350 years old) (Q1120556)

The author dates the theory of differential equations from 1638 when F. de Beaune, after reading Descartes's geometry, posed the first problems concerning the determination of curves from differential properties (involving subtangents). The Discorsi of Galileo, published the same year, also contains problems that lead to differential equations. The author gives a quick survey of some aspects of the development of the problems through the isoperimetric problems of the calculus of variations. There is some bibliography and some historically interesting problems for beginners.