APPROXIMATE DERIVATIONS MAPPING INTO THE RADICALS OF BANACH ALGEBRAS
APPROXIMATE DERIVATIONS MAPPING INTO THE RADICALS OF BANACH ALGEBRAS
In the present paper, we investigate the situations so that the generalized Hyers-Ulam-Rassias stability for functional equations $f(x^2) = f(x)x + xf(x)$ and $f(xy) = f(x)y + xf(y)$ is satisfied. As a result we obtain that every linear mapping on a commutative Banach algebra which is an $\varepsilon$-approximate derivation maps …