Question

Locate the point representing the complex numbers $z$ on the Argand diagram for which
$|i-1-2z|>9,$

Answer 1

The inequality can be written as
$|-2|=|z-\frac{i-1}{2}|>9$ or $|z-\frac{i-1}{2}|>\frac{9}{2}$
Which represents all point $z$ outside the circle
with center $\frac{(i-1)}{2}$ i.e.$(-\frac{1}{2},\frac{1}{2})$ and radius $\frac{9}{2}$.