Meromorphic Functions That Share One Finite Value CM or IM with Their First Derivative

Abstract

In this paper we shall prove that if a non-constant meromorphic function and its derivative share the value CM (IM) and if ( ), then either or ( ), where and are constants. These results give improvement and extension of the following result of Gundersen: if a non-constant meromorphic function and its derivative share two distinct values CM, then .