Jean Paul de Gua de Malves

Jean Paul de Gua de Malves (1713, Malves-en-Minervois (Aude) – June 2, 1785, Paris[1]) was a French mathematician who published in 1740 a work on analytical geometry in which he applied it, without the aid of differential calculus, to find the tangents, asymptotes, and various singular points of an algebraic curve.

He further showed how singular points and isolated loops were affected by conical projection.

He gave the proof of Descartes's rule of signs which is to be found in most modern works.

He was an early, short-lived, participant, then editor (later replaced by Diderot) of the project that ended up as the Encyclopédie.

In either case, Jean-Paul and Jean le Rond d'Alembert, also thought to have been recruited by the de Gua, first show up on the December 1746 payroll of the publishers who were backing the Encyclopédie project.