GENERALIZED QUADRATIC MAPPINGS IN 2d VARIABLES

초록

Let X, Y be vector spaces. It is shown that if an even mapping f :X → Y satisfies f(0)=0, and [수식]for all x_1, …, x(_2d) ∈ X, then the even mapping f : X → Y is quadratic. Furthermore, we prove the Hyers-Ulam stability of the above functional equation in Banach spaces.

키워드