If ${z_1}$ and ${z_2}$ are two complex numbers, then $|{z_1} - {z_2}|$ is
$ \ge \,|{z_1}| - |{z_2}|$
$ \le \,|{z_1}| - |{z_2}|$
$ \ge \,|{z_1}| + |{z_2}|$
$ \le \,|{z_2}| - |{z_1}|$
The conjugate of the complex number $\frac{{2 + 5i}}{{4 - 3i}}$ is
Find the modulus and argument of the complex number $\frac{1+2 i}{1-3 i}$
Find the modulus of $\frac{1+i}{1-i}-\frac{1-i}{1+i}$
Let $z_k=\cos \left(\frac{2 k \pi}{10}\right)+ i \sin \left(\frac{2 k \pi}{10}\right) ; k =1,2, \ldots 9$.
List $I$ | List $II$ |
$P.$ For each $z_k$ there exists a $z_j$ such that $z_k \cdot z_j=1$ | $1.$ True |
$Q.$ There exists a $k \in\{1,2, \ldots ., 9\}$ such that $z_{1 .} . z=z_k$ has no solution $z$ in the set of complex numbers. | $2.$ False |
$R.$ $\frac{\left|1-z_1\right|\left|1-z_2\right| \ldots . .\left|1-z_9\right|}{10}$ equals | $3.$ $1$ |
$S.$ $1-\sum_{k=1}^9 \cos \left(\frac{2 k \pi}{10}\right)$ equals | $4.$ $2$ |
Codes: $ \quad P \quad Q \quad R \quad S$
If $z = 1 - \cos \alpha + i\sin \alpha $, then $amp \ z$=