ABSTRACT. In this paper, we consider the general solution for a mixed type cubic functional equation lf( m−1∑ i=1 xi + lxm)+ lf( m−1∑ i=1 xi − lxm)+ 2 m−1∑ i=1 f(lxi) = 2lf( m−1∑ i=1 xi)+ l 3 m−1∑ i=1 [f(xi + xm)+ f(xi − xm)], where l ≥ 2 and m ≥ 3 are any integers and investigate the Hyers-Ulam-Rassias stability of this equation.
ABSTRACT. In this paper, we consider the general solution for a mixed type cubic functional equation lf( m−1∑ i=1 xi + lxm)+ lf( m−1∑ i=1 xi − lxm)+ 2 m−1∑ i=1 f(lxi) = 2lf( m−1∑ i=1 xi)+ l 3 m−1∑ i=1 [f(xi + xm)+ f(xi − xm)], where l ≥ 2 and m ≥ 3 are any integers and investigate the Hyers-Ulam-Rassias stability of this equation.