On the stability of a quartic functional equation

In this paper, we prove the generalized Hyers-Ularn stability for the following quartic functional equation f(2x + y) + f(2x - y) = 4f(x + y) + 4f(x - y) + 24 f(x) - 6f(y). (c) 2007 Elsevier Inc. All rights reserved.