Mathematica Eterna
Open Access

Abstract

ON THE STABILITY OF THE FUNCTIONAL EQUATION f(x + y + z + xy + yz + xz + xyz) = f(x) + f(y) + f(z) + (x + y + xy)f(z) +(y + z + yz)f(x) + (x + z + xz)f(y)

K. RAVI and S. SABARINATHAN

In this paper, we study the Hyers - Ulam stability and the Superstability of the functional equation f(x + y + z + xy + yz + xz + xyz) = f(x) + f(y) + f(z) + (x + y + xy)f(z) + (y + z + yz)f(x) + (x + z + xz)f(y).