Radius problems for a subclass of close-to-convex univalent functions

Let P[A,B], −1≤B<A≤1, be the class of functions p such that p(z) is subordinate to 1+Az1+Bz. A function f, analytic in the unit disk E is said to belong to the class Kβ*[A,B] if, and only if, there exists a function g with zg′(z)g(z)∈P[A,B] such that Re(zf′(z))′g′(z)>β, 0≤β<1 and z∈E. The f...

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Main Author: Khalida Inayat Noor
Format: Article
Language:English
Published: Hindawi Limited 1992-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S0161171292000930
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spelling doaj-8230cff7196241c2bd6d47f25331a11e2020-11-25T00:30:05ZengHindawi LimitedInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251992-01-0115471972610.1155/S0161171292000930Radius problems for a subclass of close-to-convex univalent functionsKhalida Inayat Noor0Mathematics Department, College of Science, King Saud University, Riyadh 11451, Saudi ArabiaLet P[A,B], −1≤B<A≤1, be the class of functions p such that p(z) is subordinate to 1+Az1+Bz. A function f, analytic in the unit disk E is said to belong to the class Kβ*[A,B] if, and only if, there exists a function g with zg′(z)g(z)∈P[A,B] such that Re(zf′(z))′g′(z)>β, 0≤β<1 and z∈E. The functions in this class are close-to-convex and hence univalent. We study its relationship with some of the other subclasses of univalent functions. Some radius problems are also solved.http://dx.doi.org/10.1155/S0161171292000930close-to-convexstarlike univalentconvexradius of convexity.
collection DOAJ
language English
format Article
sources DOAJ
author Khalida Inayat Noor
spellingShingle Khalida Inayat Noor
Radius problems for a subclass of close-to-convex univalent functions
International Journal of Mathematics and Mathematical Sciences
close-to-convex
starlike univalent
convex
radius of convexity.
author_facet Khalida Inayat Noor
author_sort Khalida Inayat Noor
title Radius problems for a subclass of close-to-convex univalent functions
title_short Radius problems for a subclass of close-to-convex univalent functions
title_full Radius problems for a subclass of close-to-convex univalent functions
title_fullStr Radius problems for a subclass of close-to-convex univalent functions
title_full_unstemmed Radius problems for a subclass of close-to-convex univalent functions
title_sort radius problems for a subclass of close-to-convex univalent functions
publisher Hindawi Limited
series International Journal of Mathematics and Mathematical Sciences
issn 0161-1712
1687-0425
publishDate 1992-01-01
description Let P[A,B], −1≤B<A≤1, be the class of functions p such that p(z) is subordinate to 1+Az1+Bz. A function f, analytic in the unit disk E is said to belong to the class Kβ*[A,B] if, and only if, there exists a function g with zg′(z)g(z)∈P[A,B] such that Re(zf′(z))′g′(z)>β, 0≤β<1 and z∈E. The functions in this class are close-to-convex and hence univalent. We study its relationship with some of the other subclasses of univalent functions. Some radius problems are also solved.
topic close-to-convex
starlike univalent
convex
radius of convexity.
url http://dx.doi.org/10.1155/S0161171292000930
work_keys_str_mv AT khalidainayatnoor radiusproblemsforasubclassofclosetoconvexunivalentfunctions
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