# Argand diagram

An Argand diagram is the graphical representation of complex numbers written in polar coordinates. For example, if $z\in\mathbb{C}$ is a complex number, then $z$ can be written as $re^{i\theta}$, where $r$ is the length of $z$ considered as a vector $(x,y)\in\mathbb{R}^{2}$, with $z=x+yi$, and $\theta$ is the value such that $\tan\theta=\frac{y}{x}$, and can be interpreted as the angle $z$ makes with the $x$-axis. The Argand diagram of $z$ is thus

Argand is the name of Jean-Robert Argand, the Frenchman who is credited with the geometric interpretation of the complex numbers http://www-groups.dcs.st-and.ac.uk/ history/Mathematicians/Argand.html[Biography]

Title Argand diagram ArgandDiagram 2013-03-22 11:57:25 2013-03-22 11:57:25 CWoo (3771) CWoo (3771) 10 CWoo (3771) Definition msc 28A10 msc 30-00 Complex