On the stability of a quartic functional equation

In this paper, we prove the generalized Hyers–Ulam stability for the following quartic functional equationf(2x+y)+f(2x−y)=4f(x+y)+4f(x−y)+24f(x)−6f(y).f(2x+y)+f(2x−y)=4f(x+y)+4f(x−y)+24f(x)−6f(y).