A fixed point approach to the stability of an AQCQ-functional equation in RN-spaces

Abstract

Using the fixed point method, we prove the Hyers-Ulam stability of the following additive-quadraticcubic-quartic functional equationin random normed spaces.

Stability of an Additive-Quartic Functional Equation in Orthogonality Spaces

“…By using fixed point methods, the stability problems of several functional equations have been extensively investigated by a number of authors ( [3,4,8,9,10,18,21,26,27,28,29,31,32]). …”