On normality of meromorphic functions with multiple zeros and sharing values

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 subseteq C and n be a positive integer. Let a, b be two finite complex constants such that a neq 0. If n geq 3 and f + a(f )^n and g + a(g )^n share b in D for every pair of functions f, g in F, then F is normal in D. And some examples are provided to show the result is sharp