CERTAIN CLASSES OF ANALYTIC AND MULTIVALENT FUNCTIONS WITH NEGATIVE COEFFICIENTS

Authors: M. K. AOUF, A. SHAMANDY, A.A. ATTIYIA

Abstract: We introduce a subclass K^{*}_{n+p-1}(A,B) of analytic and p-valent functions with negative coefficients. Coefficient estimates, some properties, distortion theorems and closure theorems of functions belonging to the class K^{*}_{n+p-1}(A,B) are determined. Also we obtain radii of close-to-convexity, starlikeness and convexity for the class K^{*}_{n+p-1}(A,B). We also obtain class preserving integral operator of the form F(z)=\frac{c+p}{z^c}\int_0^{z}t^{c-1}f(t) dt, c> -p for the class K^{*}_{n+p-1}(A,B) Conversely when F(z)\,\, \in K_{n+p-1}^{\star} (A,B) radius of p-valence of f(z) defined by the above equation is obtained.

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