In  this paper, we investigate the generalizedHyers-Ulam-Rassias stability for the quartic, cubic and additivefunctional equation$$f(x+ky)+f(x-ky)=k^2f(x+y)+k^2f(x-y)+(k^2-1)[k^2f(y)+k^2f(-y)-2f(x)]$$ ($k in mathbb{Z}-{0,pm1}$) in $p-$Banach spaces.

‎In this paper‎, ‎we present the‎ generalized hyperstability results of cubic functional equation in‎ ‎ultrametric Banach spaces using the fixed point method‎.

It is so common that it may be considered almost universal among second order cyberneticians, to identify second order cybernetics and radical constructivism, distinguished as opposite sides of the same coin. It is perhaps not so common that radical constructivists make this equation: they seem much more interested in the influence of radical constructivism in other subjects, especially educati...