The amplitude of $0$ is

If $z = \frac{-2}{1 + \sqrt{3}i}$,then the value of $arg(z)$ is

If $z_1 = -\sqrt{3} + i$ and $z_2 = -\sqrt{3} - i$,then the principal amplitude of the complex number $\frac{z_1}{z_2}$ is

If ${z_1}$ and ${z_2}$ are two non-zero complex numbers such that $|{z_1} + {z_2}| = |{z_1}| + |{z_2}|,$ then $\text{arg}({z_1}) - \text{arg}({z_2})$ is equal to

If $arg(z) < 0$,then $arg(-z) - arg(z)$ equals

Let $z$ be a purely imaginary number such that $\text{Im}(z) < 0$. Then $\arg(z)$ is equal to