Fuzzy stability of functional equations in n-variable fuzzy Banach spaces

Abstract

In this paper, we prove a generalized fuzzy version of the Hyers-Ulam stability for the functional equations f (phi(X)) = phi(X) f (X) + psi(X)e and f (phi(X)) = phi(X) f (X) by using the direct method and the fixed point method, where X denotes an n-variable. Furthermore, we can apply the obtained results to some well-known functional equations such as gamma-function, beta-function, and G-function type's equations.