主要研究了亚纯函数的K阶导数的不动点和小函数问题.证明了如果f(z)是个超越的亚纯函数,k是个正整数且f(z)的零点至少是k+1重,极点至少为2重,那么f^(k)(z)有无穷多个不动点.
The problems of fixed points and value distribution of K-order derivatives of meromorphic function are investigated. Let f(z) be a transcendental meromorphic function and k a positive integer and the zeros off(z) are of multiplicity at least ≥k + 1, and the poles at least 2, then f^(k)(z) has infinitely many fixed points.