If $z$ is a complex number such that $\frac{{z - 1}}{{z + 1}}$ is purely imaginary, then
$|z|\, = 0$
$|z|\, = 1$
$|z|\, > 1$
$|z|\, < 1$
If $\frac{3+i \sin \theta}{4-i \cos \theta}, \theta \in[0,2 \pi],$ is a real number, then an argument of $\sin \theta+\mathrm{i} \cos \theta$ is
The maximum value of $|z|$ where z satisfies the condition $\left| {z + \frac{2}{z}} \right| = 2$ is
The amplitude of $\frac{{1 + \sqrt 3 i}}{{\sqrt 3 + 1}}$ is
If $arg\, z < 0$ then $arg\, (-z)\, -arg(z)$ is equal to
If $z = 3 + 5i,\,\,{\rm{then }}\,{z^3} + \bar z + 198 = $