Fixed points and fuzzy stability of an additive-quadratic functional equation

Ministry of Education, Science and TechnologyThe fuzzy stability problems for the Cauchy additive functional equation and the Jensen additive functional equation in fuzzy Banach spaces have been investigated by Moslehian et al. Using fixed point method, we prove the Hyers-Ulam stability of the functional equation lf (Sigma(l)(i=1)x(i)) + Sigma(l)(i=1)f(lx(i) - Sigma(l)(i=1)d(j)) (0.1) = l(2) + l/2 Sigma(l)(i=1)f(x(i)) + l(2) - l/2 Sigma(l)(i=1)f(-x(i)) (l >= 2) in fuzzy Banach spaces.Basic Science Research Program through the National Research Foundation of Kore

The Fixed Point Method for Fuzzy Approximation of a Functional Equation Associated with Inner Product Spaces

Th. M. Rassias (1984) proved that the norm defined over a real vector space is induced by an inner product if and only if for a fixed integer ≥2,∑=1‖∑−(1/)=1‖2=∑=1‖‖2∑−‖(1/)=1‖2 holds for all 1,…,∈. The aim of this paper is to extend the applications of the fixed point alternative method to provide a fuzzy stability for the functional equation ∑=1(∑−(1/)=1∑)==1(∑)−((1/)=1) which is said to be a functional equation associated with inner product spaces

On the Stability Problem in Fuzzy Banach Space

We investigate the generalized Ulam-Hyers stability of the Cauchy functional equation and pose two open problems in fuzzy Banach space