AAHL 1.13.1 Modulus-argument form

The video explains how to express complex numbers in modulus-argument form, which is represented as $z = r(\cos \theta + i \sin \theta)$ or $z = r \text{cis} \theta$. The process involves calculating the (length) of the complex number using the Pythagorean theorem, given by , where and are the real and imaginary parts, respectively.