On close-to-convex functions of complex order

The class S*(b) of starlike functions of complex order b was introduced and studied by M.K. Aouf and M.A. Nasr. The authors using the Ruscheweyh derivatives introduce the class K(b) of functions close-to-convex of complex order b, b≠0 and its generalization, the classes Kn(b) where n is a nonnegativ...

Full description

Saved in:
Bibliographic Details
Main Authors: H. S. Al-Amiri, Thotage S. Fernando
Format: Article
Language:English
Published: Wiley 1990-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S0161171290000473
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The class S*(b) of starlike functions of complex order b was introduced and studied by M.K. Aouf and M.A. Nasr. The authors using the Ruscheweyh derivatives introduce the class K(b) of functions close-to-convex of complex order b, b≠0 and its generalization, the classes Kn(b) where n is a nonnegative integer. Here S*(b)⊂K(b)=K0(b). Sharp coefficient bounds are determined for Kn(b) as well as several sufficient conditions for functions to belong to Kn(b). The authors also obtain some distortion and covering theorems for Kn(b) and determine the radius of the largest disk in which every f∈Kn(b) belongs to Kn(1). All results are sharp.
ISSN:0161-1712
1687-0425