18. If $1 / 2 z 1 / 2 = 1$ and $\omega = z - 1 / z + 1$ (where $z \neq - 1$ ), then $\operatorname { Re } ( w )$ is:
(a) 0
(b) $\quad 1 / | z + 1 | ^ { 2 }$
(c) $\quad ( | 1 / ( z + 1 ) | ) \left( 1 / [ z + 1 ] ^ { 2 } \right)$
(d) $\quad \sqrt { } 2 / | z + 1 | ^ { 2 }$
If $z$ is a complex number satisfying $| z | = 1$ and $z \neq - 1$, then the real part of $w = \frac { z - 1 } { z + 1 }$ is
18. If $1 / 2 z 1 / 2 = 1$ and $\omega = z - 1 / z + 1$ (where $z \neq - 1$ ), then $\operatorname { Re } ( w )$ is:\\
(a) 0\\
(b) $\quad 1 / | z + 1 | ^ { 2 }$\\
(c) $\quad ( | 1 / ( z + 1 ) | ) \left( 1 / [ z + 1 ] ^ { 2 } \right)$\\
(d) $\quad \sqrt { } 2 / | z + 1 | ^ { 2 }$\\