On normality of meromorphic functions with multiple zeros and sharing values

doi:10.3906/mat-0909-37 On normality of meromorphic functions with multiple zeros and sharing values You-Ming Wang In this paper we study the problem of normal families of meromorphic functions concerning shared values. Let F be a family of meromorphic functions in the plane domain D ⊆ and n be a positive integer. Let a, b be two finite complex constants such that a = 0. If n ≥ 3 and f + a(f ′)n and g + a(g′)n share b in D for every pair of functions f, g ∈ F, then F is normal in D. And some examples are provided to show the result is sharp. Key words and phrases: Meromorphic functions, shared value, normal family. 1. Introduction an