Additive-Cubic Functional Equations from Additive Groups into Non-Archimedean Banach Spaces
M. Eshaghi Gordji, M. Bavand Savadkouhi, M. Bidkham
Inthispaper, we establish the generalized Hyres--Ulam stability of the mixed type additive-cubic functional equation $f(2x+y)+f(2x-y)=2f(x+y)+2f(x-y)+2f(2x)-4f(x)$ from additive groups into non-Archimedean Banach spaces.