Journal of Applied Mathematics (Jan 2014)
Fuzzy Stability of the Generalized Version of Drygas Functional Equation
Abstract
We consider the functional equation f(ax+y)+f(ax-y)-a(a+1)f(x)-a(a-1)f(-x)-[f(y)+f(-y)]+k[f(x+y)+f(x-y)-2f(x)-f(y)-f(-y)]=0 for a fixed rational number a with a≠1,-1,0 and a fixed real number k. We study the solution of the equation between linear spaces and prove the generalized Hyers-Ulam stability for it when the target space is a fuzzy normed space.