The General Solution of Abel-Type Functional Equations

The general measurable solution of (A) was found by Stamate 8]. Aczél 3] and Lajkô 6] proved that the general solution of (A) for unknown functions ψ, g, h: ? → ? are (1), (2) and (3), respectively. Filipescu 5] found the general measurable solution of (B). We establish an elementary prof for the general solution of equation (A) (Theorem 1.). Our method is suitable for finding the general solution of (B) (Theorem 2.).