The argument of the complex number $\sin \,\frac{{6\pi }}{5}\, + \,i\,\left( {1\, + \,\cos \,\frac{{6\pi }}{5}} \right)$ is
$\frac{{6\pi }}{5}$
$\frac{{5\pi }}{6}$
$\frac{{9\pi }}{10}$
$\frac{{2\pi }}{5}$
If the conjugate of $(x + iy)(1 - 2i)$ be $1 + i$, then
If $z$ is a complex number such that $\left| z \right| \ge 2$ , then the minimum value of $\left| {z + \frac{1}{2}} \right|$:
If $0 < amp{\rm{ (z)}} < \pi {\rm{,}}$then $amp(z)-amp ( - z) = $
If $z_1, z_2 $ are any two complex numbers, then $|{z_1} + \sqrt {z_1^2 - z_2^2} |$ $ + |{z_1} - \sqrt {z_1^2 - z_2^2} |$ is equal to
If $|{z_1}| = |{z_2}| = .......... = |{z_n}| = 1,$ then the value of $|{z_1} + {z_2} + {z_3} + ............. + {z_n}|$=