Lemma 2.1  [1]}
Let \(b \in [0,1]\)  and \(0 \le \alpha <1\) . If \(p \in \mathcal {P}_b(\alpha )\) , then for \(|z|=r<1\) ,
\(\left| \frac{zp^{\prime }(z)}{p(z)}\right| \le \frac{2(1-\alpha )r}{1-r^2} \frac{b r^2+2r+b}{(1-2\alpha )r^2+ 2b(1-\alpha ) r+1}.\) 


Лемма 2.1 [1]

Пусть \(b \in [0,1]\) и \(0 \le \alpha <1\). Если \(p \in \mathcal {P}_b(\alpha)\), то для \(|z|=r<1\):

\(\left| \frac{zp^{\prime }(z)}{p(z)}\right| \le \frac{2(1-\alpha )r}{1-r^2} \frac{b r^2+2r+b}{(1-2\alpha )r^2+ 2b(1-\alpha ) r+1}.\)