A fixed point approach to the stability of a mixed type additive and quadratic functional equation

Abstract

In this paper, we investigate the stability problems for a functional equation f (ax + y) + af (x − y) − a 2 +3a 2 f (x) − a(a−1) 2 f (−x) − f (y) − af (−y) = 0 by using the fixed point method.