International Journal of Mathematics and Mathematical Sciences
Volume 7 (1984), Issue 4, Pages 719-730
doi:10.1155/S0161171284000752
On new classes of analytic functions with negative coefficients
Shigeyoshi Owa
Department of Mathematics, Faculty of Science and Technology, Kinki University, Higashi-Osaka, Osaka, Japan
Abstract
We introduce the classes Kn* of analytic functions with negative coefficients by using the nth order Ruscheweyh derivative. The object of the present paper is to show coefficient inequalities and some closure theorems for functions f(z) in Kn*. Further we consider the modified Hadamard product of functions fi(z) in Kni*(n=1,2,…,m).