A FIXED POINT APPROACH TO THE STABILITY OF QUADRATIC FUNCTIONAL EQUATION

A fixed point approach to the stability of additive-quadratic-quartic functional equations

In this article, we introduce a class of the generalized mixed additive, quadratic and quartic functional equations and obtain their common solutions. We also investigate the stability of such modified functional equations in the non-Archimedean normed spaces by a fixed point method.

A Fixed Point Approach to Stability of a Quadratic Equation

Using the fixed point alternative theorem we establish the orthogonal stability of quadratic functional equation of Pexider type f(x + y) + g(x − y) = h(x) + k(y), where f, g, h, k are mappings from a symmetric orthogonality space to a Banach space, by orthogonal additive mappings under a necessary and sufficient condition on f .

A fixed-point approach to the stability of a functional equation on quadratic forms

* Correspondence: [email protected] Department of Mathematics Education, College of Education, Mokwon University, Daejeon, 302729, Korea Full list of author information is available at the end of the article Abstract Using the fixed-point method, we prove the generalized Hyers-Ulam stability of the functional equation f (x + y, z + w) + f (x− y, z− w) = 2f (x, z) + 2f (y,w). The quadratic for...

A Fixed Point Approach to the Stability of a Mixed Type Additive and Quadratic Functional Equation

In this paper, we investigate the stability problems for a functional equation f(ax + y) + af(x − y) − a2+3a 2 f(x) −a(a−1) 2 f(−x)− f(y) − af(−y) = 0 by using the fixed point method. Mathematics Subject Classification: Primary 39B82, 39B62; Secondary 47H10

A Fixed Point Approach to the Stability of the Cauchy Additive and Quadratic Type Functional Equation