Radius Constants for Analytic Functions with Fixed Second Coefficient
Let f(z) = z +∑n=2∞anzn 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 an≤cn+d (c,d≥0) or an≤c/n (c>0 and n≥3). Other radius constants are also obtained f...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Hindawi Limited
2014-01-01
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| Series: | The Scientific World Journal |
| Online Access: | http://dx.doi.org/10.1155/2014/898614 |
| Summary: | Let f(z) = z +∑n=2∞anzn 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 an≤cn+d (c,d≥0) or an≤c/n (c>0 and n≥3). Other radius constants are also obtained for these functions, and connections with earlier results are made. |
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| ISSN: | 2356-6140 1537-744X |