On Univalent Functions with Negative and Missing Coefficients

Let P（A,B）be the class of functions f（z）=z-sum from n=k to ∞ |α|z,K≥2,regular in the unit disc U={Z:|Z|<1}and satisfying |[f＇（z）-1]/[A-Bf＇（z）]|<1 for z∈U,where -1≤B<≤1.In this paper we obtain coefficient estimate,disrortion and closure theorems and radius of covexity for the class P（A,B） under the assumption -1≤B≤0.We also obtain class preserving integral operators of the form F（z）=（c+1）/Zintegral from n=0 to z (t)f（t）dt.c>-1 for the class P（A,B）.Conversely when F∈P（A,B）,radius of univalence of f has been deterined.