Advances in Pure Mathematics, 2017, 7, 641-646
http://www.scirp.org/journal/apm
ISSN Online: 2160-0384
ISSN Print: 2160-0368
DOI: 10.4236/apm.2017.711038 Nov. 24, 2017 641 Advances in Pure Mathematics
On a Subordination Result of a Subclass
of Analytic Functions
Risikat Ayodeji Bello
Department of Mathematics and Statistics, College of Pure and Applied Science, Kwara State University, Malete, Nigeria
Abstract
In this paper, we investigate a subordination property and the coefficient in-
equality for the class ( ) 1, M b , The lower bound is also provided for the real
part of functions belonging to the class ( ) 1, M b .
Keywords
Analytic Function, Univalent Function, Hadamard Product,
Subordination
1. Introduction
Let A denote the class of function () f z analytic in the open unit disk
{ }
: 1 U z z = ∈ < and let S be the subclass of A consisting of functions
univalent in U and have the form
()
2
,
k
k
k
f z z az
∞
=
= +
∑
(1.1)
The class of convex functions of order
α in U, denoted as ( ) K α is given
by
( )
()
()
: 1 , 0 1,
zf z
K f S Re z U
f z
α α α
′′
= ∈ + > ≤ < ∈
′
Definition 1.1. The Hadamard product or convolution f g ∗ of the func-
tion () f z and () gz , where () f z is as defined in (1.1) and the function
() gz is given by
()
2
,
k
k
k
gz z bz
∞
=
= +
∑
is defined as:
How to cite this paper: Bello, R.A.
(2017) On a Subordination Result of a
Subclass of Analytic Functions. Advances
in Pure Mathematics, 7, 641-646.
https://doi.org/10.4236/apm.2017.711038
Received: March 13, 2017
Accepted: November 21, 2017
Published: November 24, 2017
Copyright © 2017 by author and
Scientific Research Publishing Inc.
This work is licensed under the Creative
Commons Attribution International
License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
Open Access