Formula
$$\dfrac{z_1}{z_2} = \dfrac{r_1\left(\cos\psi_1+i\sin\psi_1\right)}{r_2\left(\cos\psi_2+i\sin\psi_2\right)}=\dfrac{r_1}{r_2}\left(\cos(\psi_1-\psi_2) + i\sin(\psi_1-\psi_2)\right)$$
$$\dfrac{z_1}{z_2} = \dfrac{r_1\left(\cos\psi_1+i\sin\psi_1\right)}{r_2\left(\cos\psi_2+i\sin\psi_2\right)}=\dfrac{r_1}{r_2}\left(\cos(\psi_1-\psi_2) + i\sin(\psi_1-\psi_2)\right)$$