Radius constants for analytic functions with fixed second coefficient.
| Autor: | Nargesi MM; Department of Mathematics, College of Natural Sciences & Mathematics, California State University, 800 North State College Boulevard, Fullerton, CA 92831-3599, USA., Ali RM; School of Mathematical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia., Ravichandran V; Department of Mathematics, University of Delhi, Delhi 110 007, India. |
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| Jazyk: | angličtina |
| Zdroj: | TheScientificWorldJournal [ScientificWorldJournal] 2014; Vol. 2014, pp. 898614. Date of Electronic Publication: 2014 Jul 01. |
| DOI: | 10.1155/2014/898614 |
| Abstrakt: | Let f(z) = z + ∑(n=2)(∞) (a)n(z) (n) be analytic in the unit disk with the second coefficient a2 satisfying |a2| = 2b, 0 ≤ b ≤ 1. Sharp radius of Janowski starlikeness is obtained for functions f whose nth coefficient satisfies |a(n)| ≤ cn + d (c, d ≥ 0) or |a(n)| ≤ c/n (c > 0 and n ≥ 3). Other radius constants are also obtained for these functions, and connections with earlier results are made. |
| Databáze: | MEDLINE |
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