Solution and Hyers‐Ulam‐Rassias Stability ofGeneralized Mixed Type Additive‐QuadraticFunctional Equations in Fuzzy Banach Spaces

Abstract

By using fixed point methods and direct method, we establish the generalized Hyers-Ulam stability of the following additive-quadratic functional equationf(x+ky)+f(x−ky)=f(x+y)+f(x−y)+(2(k+1)/k)f(ky)−2(k+1)f(y)for fixed integerskwithk≠0,±1in fuzzy Banach spaces.