where \(\pi /2\le \delta <\pi \) . The class \(\mathcal {M}(\delta )\)  was introduced by Kargar et al. [1]}.
Moreover, by definition of subordination, \(f\in \mathcal {M}(\delta )\)  if, and
only if
\(\left(\frac{z f^{\prime }(z)}{f(z)}-1\right)\prec \mathcal {B}_\delta (z)\quad (z\in \Delta ),\) 

где \(\pi /2\le \delta <\pi \). Класс \(\mathcal {M}(\delta )\) был представлен Kargar et al. [1].

Более того, по определению подчинения, \(f\in \mathcal {M}(\delta )\) если и только если

\(\left(\frac{z f^{\prime }(z)}{f(z)}-1\right)\prec \mathcal {B}_\delta (z)\quad (z\in \Delta ),\)