Upper bound of Hankel determinant for a class of analytic functions

Abstract

The aim of this study is to solve the Fekete-Szego problem and to define upper bound for Hankel determinant H2(1) in a novel class K of analytical functions in the unit disc. Moreover, in a class of analytic functions on the unit disc, assuming the existence of angular limit on the boundary point, the estimations below of the modulus of angular derivative have been obtained