Argand system

In mathematics, an "n"th-order Argand system (named after French mathematician Jean-Robert Argand) is a coordinate system constructed around the "n"th roots of unity. From the origin, "n" axes extend such that the angle between each axis and the axes immediately before and after it is 360/"n" degrees. For example, the number line is the 2nd-order Argand system because the two axes extending from the origin represent 1 and −1, the 2nd roots of unity. The complex plane (sometimes called the Argand plane, also named after Argand) is the 4th-order Argand system because the 4 axes extending from the origin represent 1, "i", −1, and −"i", the 4th roots of unity.