If $|z_1|=1, \, |z_2| =2, \,|z_3|=3$ and $|9z_1z_2 + 4z_1z_3+z_2z_3| =12$ then the value of $|z_1+z_2+z_3|$ is equal to :-
$2$
$3$
$4$
$6$
The conjugate of a complex number is $\frac{1}{{i - 1}}$ then that complex number is
The value of $|z - 5|$if $z = x + iy$, is
If $5 + ix^3y^2$ and $x^3 + y^2 + 6i$ are conjugate complex numbers and arg $(x + iy) = \theta $ , then ${\tan ^2}\,\theta $ is equal to
If $z$ is a complex number such that $\frac{{z - 1}}{{z + 1}}$ is purely imaginary, then
If $|z|\, = 4$ and $arg\,\,z = \frac{{5\pi }}{6},$then $z =$