Topic summary
Jean-Robert Argand
Jean-Robert Argand (UK: , US: , French:; July 18, 1768 – August 13, 1822) was a Genevan amateur mathematician. In 1806, while managing a bookstore in Paris, he published the idea of the geometrical interpretation of complex numbers known as the Argand diagram and is known for the first rigorous proof of the fundamental theorem of algebra.