On the Ulam-Hyers stability of a quadratic functional equation

Abstract

Abstract The Ulam-Hyers stability problems of the following quadratic equation r 2 f x + y r + r 2 f x - y r = 2 f ( x ) + 2 f ( y ) , where r is a nonzero rational number, shall be treated. The case r = 2 was introduced by J. M. Rassias in 1999. Furthermore, we prove the stability of the quadratic equation by using the fixed point method. 2010 Mathematics Subject Classification: 39B22; 39B52; 39B72.

Keywords

• Hyers-Ulam stability
• quadratic function