Investigations on the Hyers–Ulam stability of generalized radical functional equations.

In (Brzdęk and Schwaiger in Aeq Math 92: 975–991, 2018) solutions of far reaching generalizations of the so-called radical functional equation f (p (π (x) + π (y))) = f (x) + f (y) have been investigated. These investigations are continued here by analysing the corresponding stability results, which have been the main subject of several recent papers. We propose a very general and uniform approach. [ABSTRACT FROM AUTHOR]