Question

locate the points representing the complex number $z$ for which
$\left|\pi \arg z\right|<\pi /4$.

Answer 1

$|\pi -\arg z|<\pi /4$
$\Rightarrow -\pi /4<\pi -\arg z<\pi /4$
$\Rightarrow -5\pi /4<-\arg z<-3\pi /4$
$\Rightarrow 5\pi /4>\arg z>3\pi /4$
$\Rightarrow 3\pi /4<\arg z<5\pi /4$