In this paper, we obtain the general solution and the generalized Hyers-Ulam stability for quadratic functional equations f(2x+ y)+ f(2xâˆ’ y) = f(x+ y)+ f(xâˆ’ y)+6f(x) andf(2x + y) + f(x + 2y) = 4f(x +â€¦ (More)

In this paper, we solve the generalized Hyers-Ulam-Rassias stability problem for a cubic functional equation f (x + 2y) + f (xâˆ’ 2y) + 6f (x) = 4f (x + y) + 4f (xâˆ’ y) in the spirit of Hyers, Ulam,â€¦ (More)

The purpose of this paper is to solve the generalized Hyersâ€“Ulam stability problem for a k â€“additive functional equation Dm,if (x, y) = 0, on the basis of direct method, where k=4m+i is a positiveâ€¦ (More)