On meromorphic functions that share one value with their derivative
Abstract The following theorem has been proved by R.Brück. If a non-constant entire function ƒ and its derivative ƒ′ share the value 1 CM (counting multiplicities), and if , then ƒ′- 1 = c ( ƒ - 1 ) for some nonzero constant c . In this paper we shall prove that the above result is also true when ƒ is a non-constant meromorphic function.