关于f'f^n值分布的一个结果

A Result On the Distribution of Values of f＇f^n

设f（z）是开平面上的超越亚纯函数，a是异于零的有穷复数，仪洪勋对f＇f－a的零点个数给出定量估计，改进了J．Clunie，J．M．Anderson，I．N．Baker和J．G．Clunie等人的有关定理。设n是任意的正整数，本文对f＇fn─a的零点个数给出定量估计，推广了仪洪勋所得到的有关结果。

Let f be a transcendental meromorphic function satisfying N (r,f) = S (r,f),and let a be a non－zero finite complexnumber, Yi Hongxun gave the quantitative estimation for the number of zeros of F f－ a, and improved the relative theorems due to J. clunie , J. M. Anderson. I. N. Baker and J. G. Clunle. In this paper we give the quantitatitve estimation for the number of zeros of f' fn － a .where n is an arbitrary positive inleger, and generalize the relative results obtained by Yi Hongxun