Abstract Let H H be the space of all functions that are analytic in D D. Let A A denote the family of all functions f ∈ H f H and normalized by the conditions f (0) = 0 = f ′ (0) − 1. Obradović and Ponnusamy have introduced the class M (λ) M () such that the functions in M (λ) M () are univalent in D D whenever 0 M M, where the analytic functions belongs to some suitable subclasses of S S, the class of univalent functions from A A.
Biswas et al. (Sun,) studied this question.