Journal of Inequalities and Applications
Volume 2010 (2010), Article ID 476249, 15 pages
doi:10.1155/2010/476249
Research Article

Hyers-Ulam Stability of a Bi-Jensen Functional Equation on a Punctured Domain

Gwang Hui Kim1 and Yang-Hi Lee2

1Department of Mathematics, Kangnam University, Yongin, Gyeonggi 446-702, South Korea
2Department of Mathematics Education, Gongju National University of Education, Gongju 314-711, South Korea

Received 16 November 2009; Revised 8 February 2010; Accepted 15 February 2010

Academic Editor: Yong Zhou

Copyright © 2010 Gwang Hui Kim and Yang-Hi Lee. 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 Hyers-Ulam stability of a bi-Jensen functional equation: 2f((x+y)/2,z)−f(x,z)−f(y,z)=0 and simultaneously 2f(x,(y+z)/2)−f(x,y)−f(x,z)=0. And we get its stability on the punctured domain.