A Fixed Point Approach to the Fuzzy Stability of an AQCQ-Functional Equation

Choonkil Park, Dong Yun Shin, Reza Saadati, Jung Rye Lee

In [32,33], the fuzzy stability problems for the Cauchy additive functional equation and the Jensen additive functional equation in fuzzy Banach spaces have been investigated. Using the fixed point method, we prove the Hyers--Ulam stability of the following additive-quadraticcubic-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 fuzzy Banach spaces.