A unified approach to radius of convexity problems for certain classes of univalent analytic functions

We consider functions f analytic in the unit disc and assume the power series representation of the form f(z)=z+an+1zn+1+an+2zn+2+… where an+1 is fixed throughout. We provide a unified approach to radius convexity problems for different subclasses of univalent analytic functions. Numerous earlier es...

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Main Authors: M. L. Mogra, O. P. Juneja
Format: Article
Language:English
Published: Wiley 1984-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S016117128400048X
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author M. L. Mogra
O. P. Juneja
author_facet M. L. Mogra
O. P. Juneja
author_sort M. L. Mogra
collection DOAJ
description We consider functions f analytic in the unit disc and assume the power series representation of the form f(z)=z+an+1zn+1+an+2zn+2+… where an+1 is fixed throughout. We provide a unified approach to radius convexity problems for different subclasses of univalent analytic functions. Numerous earlier estimates concerning the radius of convexity such as those involving fixed second coefficient, n initial gaps, n+1 symmetric gaps, etc. are discussed. It is shown that several known results, follow as special cases of those presented in this paper.
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series International Journal of Mathematics and Mathematical Sciences
spelling doaj-art-783067e26a5b40669fe07397053df5172025-02-03T01:04:15ZengWileyInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251984-01-017344345410.1155/S016117128400048XA unified approach to radius of convexity problems for certain classes of univalent analytic functionsM. L. Mogra0O. P. Juneja1School of Mathematical Sciences, University of Khartoum, P.O. Box 321, Khartoum, SudanDepartment of Mathematics, Indian Institute of Technology, Kanpur 208016, IndiaWe consider functions f analytic in the unit disc and assume the power series representation of the form f(z)=z+an+1zn+1+an+2zn+2+… where an+1 is fixed throughout. We provide a unified approach to radius convexity problems for different subclasses of univalent analytic functions. Numerous earlier estimates concerning the radius of convexity such as those involving fixed second coefficient, n initial gaps, n+1 symmetric gaps, etc. are discussed. It is shown that several known results, follow as special cases of those presented in this paper.http://dx.doi.org/10.1155/S016117128400048Xradius of convexityunivalent functionsstarlike functions of order α and type β(n+1)-fold symmetric functionsfunctions with positive real part.
spellingShingle M. L. Mogra
O. P. Juneja
A unified approach to radius of convexity problems for certain classes of univalent analytic functions
International Journal of Mathematics and Mathematical Sciences
radius of convexity
univalent functions
starlike functions of order α and type β
(n+1)-fold symmetric functions
functions with positive real part.
title A unified approach to radius of convexity problems for certain classes of univalent analytic functions
title_full A unified approach to radius of convexity problems for certain classes of univalent analytic functions
title_fullStr A unified approach to radius of convexity problems for certain classes of univalent analytic functions
title_full_unstemmed A unified approach to radius of convexity problems for certain classes of univalent analytic functions
title_short A unified approach to radius of convexity problems for certain classes of univalent analytic functions
title_sort unified approach to radius of convexity problems for certain classes of univalent analytic functions
topic radius of convexity
univalent functions
starlike functions of order α and type β
(n+1)-fold symmetric functions
functions with positive real part.
url http://dx.doi.org/10.1155/S016117128400048X
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