Stability for the functional equation of cubic type

In this article, we establish the stability of the orthogonally cubic type functional equation (1.2) for all x1,x2,x3 with xi⊥xj (i,j=1,2,3), where ⊥ is the orthogonality in the sense of Rätz, and investigate the stability of the n-dimensional cubic type functional equation (1.3), where n⩾3 is an integer.