International Journal of Mathematics and Mathematical Sciences
Volume 2007 (2007), Article ID 62925, 7 pages
Sufficient Conditions for Janowski Starlikeness
School of Mathematical Sciences, Universiti Sains Malaysia, Penang 11800 USM, Malaysia
Received 10 March 2007; Revised 15 June 2007; Accepted 4 July 2007
Academic Editor: Teodor Bulboaca
Copyright © 2007 Rosihan M. Ali et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Let and let be an analytic function defined on the open unit disk, . Conditions on , , , and are determined so that being subordinated to implies that is subordinated to . Similar results are obtained by considering the expressions
and . These results are then applied to obtain sufficient conditions for analytic functions to be Janowski starlike.