An additive-quadratic-cubic-quartic functional equation in fuzzy Banach spaces

Abstract

Using the fixed point method, we prove the generalized Hyers-Ulam stability of the following additive-quadratic-

cubic-quartic functional equation \begin{eqnarray*} f(x+2y)+f(x-2y)& = & 4f(x+y)+4f(x-y) - 6 f(x) \\ + f(2y) & + & f(-2y) - 4f(y) - 4 f(-y) \end{eqnarray*} in fuzzy Banach spaces.