Advances in Difference Equations
Volume 2009 (2009), Article ID 826130, 17 pages
doi:10.1155/2009/826130

Solution and stability of a mixed type additive, quadratic, and cubic functional equation

M.Eshaghi Gordji1 , S.Kaboli Gharetapeh2 , J.M. Rassias3 and S. Zolfaghari1

1Department of Mathematics, Semnan University, P.O. Box 35195-363, Semnan, Iran
 2Department of Mathematics, Payame Noor University of Mashhad, Mashhad, Iran
 3Section of Mathematics and Informatics, Pedagogical Department, National and Capodistrian University of Athens, 4 Agamemnonos St., Aghia Paraskevi, Athens 15342, Greece

Abstract

We obtain the general solution and the generalized Hyers-Ulam-Rassias stability of the mixed type additive, quadratic, and cubic functional equation f(x+2y)−f(x−2y)=2(f(x+y)−f(x−y))+2f(3y)−6f(2y)+6f(y).