Document Type : Original Article


Department of Medical Radiation Engineering, Centetal Tehran Branch, Islamic Azad University,Tehran,Iran


In this paper, we introduce and obtain the general solution of a new mixed type quadratic-cubic functional equation. We investigate the stability of such functional equations in the modular space $X_\rho$ by applying $\Delta_2$-condition and the Fatou property (in some results) in the modular function $\rho$.