Radius Constants of Sigmoid Starlike Functions

Priyanka Goel, S. Sivaprasad Kumar

In the present investigation, we study the class of Sigmoid starlike functions, given by ${\mathcal{S}}_{SG}^{\ast }=\{f\in \mathcal{A}:z{f}^{\prime }(z)/f(z)\prec 2/(1+e^{-z})\}$ in context of e…