Division of Complex Numbers in Polar Form

Theorem
Let $z_1 := \left\langle{r_1, \theta_1}\right\rangle$ and $z_2 := \left\langle{r_2, \theta_2}\right\rangle$ be complex numbers expressed in polar form, such that $z_2 \ne 0$.

Then:
 * $\dfrac {z_1} {z_2} = \dfrac {r_1} {r_2} \left({\cos \left({\theta_1 - \theta_2}\right) + i \sin \left({\theta_1 - \theta_2}\right)}\right)$