Generalized Hyers-Ulam stability of quadratic functional inequality
Summary: We establish the general solution of the functional inequality \(||f(x-y)+f(y-z)+f(x-z)-3f(x)-3f(y)-3f(z)||\leqslant||f(x+y+z)||\) and then investigate the generalized Hyers-Ulam stability of this inequality in Banach spaces and in non-Archimedean Banach spaces.
scientific article; zbMATH DE number 6307006
scientific article