Comment on ‘Approximate ∗-derivations and approximate quadratic ∗-derivations on "Equation missing" -algebras’ [Jang, Park, J. Inequal. Appl. 2011 (2011), Article ID 55]

Abstract

In (J. Inequal. Appl. 2011:Article ID 55, Section 4, 2011), Jang and Park proved the Hyers-Ulam stability of quadratic *-derivations on Banach *-algebras. One can easily show that all the quadratic *-derivations δ in Section 4 must be trivial. So the results are trivial. In this paper, we correct the statements and prove the corrected results.