Coefficient Conditions for Starlikeness of Nonnegative Order

Sufficient conditions on a sequence {ak} of nonnegative numbers are obtained that ensures f(z)= E°°k=1 akzk is starlike of nonnegative order in the unit disk. A result of Vietoris on trigonometric sums is extended in this pursuit. Conditions for close to convexity and convexity in the direction of...

Full description

Saved in:
Bibliographic Details
Main Authors: M. Ali, Rosihan, See, Keong Lee, R. Mondal, Saiful
Format: Article
Language:English
Published: Hindawi Publishing Corporation 2012
Subjects:
Online Access:http://eprints.usm.my/38458/1/Coefficient_Conditions_for_Starlikeness_of_Nonnegative_Order.pdf
http://eprints.usm.my/38458/
https://doi.org/10.1155/2012/450318
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Sufficient conditions on a sequence {ak} of nonnegative numbers are obtained that ensures f(z)= E°°k=1 akzk is starlike of nonnegative order in the unit disk. A result of Vietoris on trigonometric sums is extended in this pursuit. Conditions for close to convexity and convexity in the direction of the imaginary axis are also established. These results are applied to investigate the starlikeness of functions involving the Gaussian hypergeometric functions.