Journal of Inequalities and Applications
Volume 2010 (2010), Article ID 151547, 9 pages
doi:10.1155/2010/151547
Research Article

Stability of a Cauchy-Jensen Functional Equation in Quasi-Banach Spaces

Jae-Hyeong Bae1 and Won-Gil Park2

1College of Liberal Arts, Kyung Hee University, Yongin 446-701, South Korea
2Division of Computational Sciences in Mathematics, National Institute for Mathematical Sciences, 385-16 Doryong-Dong, Yuseong-Gu, Daejeon 305-340, South Korea

Received 16 October 2009; Accepted 30 January 2010

Academic Editor: Yeol Je Cho

Copyright © 2010 Jae-Hyeong Bae and Won-Gil Park. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We obtain the generalized Hyers-Ulam stability of the Cauchy-Jensen functional equation 2f(x+y,(z+w)/2)=f(x,z)+f(x,w)+f(y,z)+f(y,w).