Abstract: In this paper, the authors investigate the Hyers-Ulam-Rassias
stability, Ulam-Gavruta-Rassias stability and J. M. Rassias mixed type product -
sum of powers of norms stability of an orthogonally quadratic functional
equation of the form
where is a
mapping from an orthogonality normed space A
into a Banach space B, is
orthogonality in the sense of Ratz with for all
Keywords and phrases: Hyers-Ulam-Rassias stability, Ulam-Gavruta-Rassias stability, J. M. Rassias mixed type product - sum of powers of norms stability, orthogonally quadratic functional equation, orthogonality space, quadratic mapping.
