Alexander [1] was the first to introduce certain subclasses of univalent functions examining the geometric properties of the image f(D) of D under f . The convex functions are those that map D onto a convex set. A function w = f(z) is said to be starlike if, together with any of its points w, the image f(D) contains the entire segment {tw : 0 ≤ t ≤ 1}. Thus we introduce the denotations S = {f ∈...

which are analytic in the open unit disc U {z ∈ C : |z| < 1} on the complex plane C. Let S, S∗ α , C α 0 ≤ α < 1 denote the subclasses of A consisting of functions that are univalent, starlike of order α, and convex of order α in U, respectively. In particular, the classes S∗ 0 S∗ and C 0 C are the familiar classes of starlike and convex functions inU, respectively. A function f ∈ C α if Re 1 z...

The class of univalent harmonic functions on the unit disc satisfying the condition ∑∞ k=2 (k m − αk)(|ak|+ |bk|) ≤ (1−α)(1−|b1|) is given. Sharp coefficient relations and distortion theorems are given for these functions. In this paper we find that many results of Özturk and Yalcin [5] are incorrect. Some of the results of this paper correct the theorems and examples of [5]. Further, sharp coe...

We will give the relation between the class of Janowski starlike functions of complex order and the class of Janowski convex functions of complex order. As a corollary of this relation, we obtain the radius of starlikeness for the class of Janowski convex functions of complex order. 1. Introduction. Let F be the class of analytic functions in D = {z | |z| < 1}, and let S denote those functions ...

In this paper we obtain upper bounds for the second Hankel determinant H2(2) of the classes bi-starlike and bi-convex functions of order β, which we denote by S∗ σ(β) and Kσ(β), respectively. In particular, the estimates for the second Hankel determinat H2(2) of bi-starlike and bi-convex functions which are important subclasses of bi-univalent functions are pointed out.

Abstract. The author here wish to further study the new concept of analytic and univalent functions normalized with f(ω) and f ′(ω) − 1 = 0 introduced by Kanas and Ronning in 1999 which was later also investigated in 2005 by Acu and Owa. The author in this paper obtain coefficient estimates, distortion theorems, convex linear combinations, and radii of ω-closeto-convex, ω − starlikeness and ω −...