Complex numbers can be represented in either the cartesian coordinate system ($ z = a + bi $) or the polar coordinate system ($ z = re^{\theta i} $). Here, operations in the polar system will be explained.

Polar Form

One can convert from cartesian to polar with the following formulas:

$ r = \sqrt{a^2 + b^2} $
$ \theta = \arctan(\frac{b}{a}) $

In the polar system, multiplication and division are easier than in the cartesian system.

Multiplication of two polar coordinates:

$ r_1e^{\theta_1i} * r_2e^{\theta_2i} = r_1r_2e^{(\theta_1+\theta_2)i} $

Division of two polar coordinates:

$ \frac{r_1e^{\theta_1i}}{r_2e^{\theta_2i}} = \frac{r_1}{r_2}e^{(\theta_1-\theta_2)i} $

Alumni Liaison

Ph.D. on Applied Mathematics in Aug 2007. Involved on applications of image super-resolution to electron microscopy

Francisco Blanco-Silva