Complex Numbers & Argand Diagrams (Edexcel A-Level Further Mathematics): Flashcards

Distance from origin on Argand diagram

$|z| = \sqrt{a^2 + b^2}$

$|z|$

Angle $\theta$ with positive real axis

$\arg(z)$

$\theta = \tan^{-1}\left(\frac{b}{a}\right)$ (adjust for quadrant)

Radians

Real part of complex number

Imaginary part of complex number

$z = |z|(\cos \theta + i \sin \theta)$