The conjugate of a complex number is $\frac{1}{i - 1}$. Then,the complex number is:

Let $z$ be a complex number such that $|z|+z=2+i$,where $i=\sqrt{-1}$. Then $|z|$ is equal to:

$\frac{1 - i}{1 + i}$ is equal to

If $z$ is a complex number such that $\left|z-\frac{4}{z}\right|=2$,then the greatest value of $|z|$ is

If $|z| = 1$ and $\omega = \frac{z - 1}{z + 1}$ (where $z \neq -1$),then $\text{Re}(\omega)$ is

If $|a_k| < 1, \lambda_k \ge 0$ for $k = 1, 2, ..., n$ and $\lambda_1 + \lambda_2 + ... + \lambda_n = 1$,then the value of $|\lambda_1 a_1 + \lambda_2 a_2 + ... + \lambda_n a_n|$ is