Coefficient inequality for parabolic starlike functions of order alpha

摘要

The aim of this paper is to obtain a sharp upper bound to the second Hankel determinant |a2a4 ? a23| for the function f when it belongs to the class of parabolic starlike functions of order α(0 ≤ α < 1). Further, an upper bound for the inverse function of f to the non-linear functional |t2t4 ? t23| was determined when it belongs to the same class of functions, using Toeplitz determinants.