Meromorphic Functions Sharing Two or Three Values with Their Derivatives in Some Angular Domains

摘要

We study the uniqueness of transcendental meromorphic functions sharing two or three values with their derivatives in some angular domains instead of the whole complex plane. The obtained results extend the corresponding results of Frank-Weissenborn and Frank-Schick, and improve Theorems 1-3 from Zheng . Some examples are given to show that the obtained results, in a sense, are the best possible.