The stability problem of functional equations is originated from a question of Ulam 1 concerning the stability of group homomorphisms. Hyers 2 gave a first affirmative partial answer to the question of Ulam for Banach spaces. Hyers’ Theorem was generalized by Aoki 3 for additive mappings and by Th. M. Rassias 4 for linear mappings by considering an unbounded Cauchy difference. The paper of Th. ...

In this paper, we prove the generalized Hyers-Ulam(or Hyers-Ulam-Rassias ) stability of the following composite functional equation f(f(x)-f(y))=f(x+y)+f(x-y)-f(x)-f(y) in various normed spaces.

in this paper, we use the denition of fuzzy normed spaces givenby bag and samanta and the behaviors of solutions of the additive functionalequation are described. the hyers-ulam stability problem of this equationis discussed and theorems concerning the hyers-ulam-rassias stability of theequation are proved on fuzzy normed linear space.

Recently the generalizedHyers-Ulam orHyers-Ulam-Rassias stability of the following functional equation ∑m j 1 f −rjxj ∑ 1≤i≤m,i / j rixi 2 ∑m i 1 rif xi mf ∑m i 1 rixi where r1, . . . , rm ∈ R, proved in Banach modules over a unital C∗-algebra. It was shown that if ∑m i 1 ri / 0, ri, rj / 0 for some 1 ≤ i < j ≤ m and a mapping f : X → Y satisfies the above mentioned functional equation then the...

Recently, in [5], Najati and Moradlou proved Hyers-Ulam-Rassias stability of the following quadratic mapping of Apollonius type Q(z − x) + Q(z − y) = 1 2 Q(x− y) + 2Q ( z − x + y 2 ) in non-Archimedean space. In this paper we establish Hyers-Ulam-Rassias stability of this functional equation in random normed spaces by direct method and fixed point method. The concept of Hyers-Ulam-Rassias stabi...

The stability problem of functional equations originated from a question of Ulam 1 concerning the stability of group homomorphisms. Hyers 2 gave a first affirmative partial answer to the question of Ulam for Banach spaces. Hyers’ theorem was generalized by Aoki 3 for additive mappings and by Rassias 4 for linear mappings by considering an unbounded Cauchy difference. The paper of Rassias 4 has ...

In this work, we present sufficient conditions in order to establish different types of Ulam stabilities for a class higher integro-differential equations. particular, consider new kind stability, the σ-semi-Hyers-Ulam which is some sense between Hyers–Ulam and Hyers–Ulam–Rassias stabilities. These result from application Banach Fixed Point Theorem, by applying specific generalization Bielecki ...

Received Okt 2, 2014 Revised Nov 1, 2014 Accepted Nov 23, 2014 In this paper, a generalization to nonlinear systems is proposed and applied to the motordynamic, rotor model and stator model in DC motor equation. We argue that Ulam-Hyers stability concept is quite significant in design problems and in design analysis for the class of DC motor’s parameters. We prove the stability of nonlinear par...

in this paper, we prove the generalized hyers-ulam(or hyers-ulam-rassias ) stability of the following composite functional equation f(f(x)-f(y))=f(x+y)+f(x-y)-f(x)-f(y) in various normed spaces.

The functional equation f(3x) = 4f(3x−3)+f(3x− 6) will be solved and its Hyers-Ulam stability will be also investigated in the class of functions f : R → X , where X is a real Banach space. Keywords—Functional equation, Lucas sequence of the first kind, Hyers-Ulam stability.