● $\displaystyle\rho_1 e^{i\theta_1}\times \rho_2 e^{i\theta_2}=\rho_1\rho_2e^{i\left(\theta_1+\theta_2\right)}$;

● $\displaystyle\frac{\rho_1 e^{i\theta_1}}{\rho_2 e^{i\theta_2}}=\frac{\rho_1}{\rho_2}e^{i\left(\theta_1-\theta_2\right)}$;

● $\displaystyle\left(\rho e^{i\theta}\right)^n=\rho^ne^{in\theta}$.