# Definition of Argand diagram in English:

## Argand diagram

### noun

Mathematics
• A diagram on which complex numbers are represented geometrically using Cartesian axes, the horizontal coordinate representing the real part of the number and the vertical coordinate the complex part.

• ‘Of course it is not unreasonable to call the geometrical interpretation of complex numbers the Argand diagram since it was Argand's work which was influential.’
• ‘In this paper he interpreted i as a rotation of the plane through 90 so giving rise to the Argand plane or Argand diagram as a geometrical representation of complex numbers.’
• ‘We can plot a complex function on an Argand diagram, that is, a function whose values are complex numbers.’
• ‘The Argand diagram is taught to most school children who are studying mathematics and Argand's name will live on in the history of mathematics through this important concept.’

### Origin

Early 20th century: named after J. R. Argand (1768–1822), French mathematician.

/ˈɑːɡənd/