Fixed Point Theory and Applications
Volume 2010 (2010), Article ID 185780, 16 pages
doi:10.1155/2010/185780
A fixed point approach to the stability of an additive-quadratic-cubic-quartic functional equation
Jung Rye Lee1
, Ji-Hye Kim2
and Choonkil Park2
1Department of Mathematics, Daejin University, Kyeonggi 487-711, South Korea
2Department of Mathematics, Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, South Korea
Abstract
Using the fixed point method, we prove the generalized Hyers-Ulam stability of the following additive-quadratic-cubic-quartic functional equation f(x+2y)+f(x−2y)=4f(x+y)+4f(x−y)−6f(x)+f(2y)+f(−2y)−4f(y)−4f(−y) in Banach spaces.