I'm just gonna bring that 1 4th out front. So it's going to be 1 4th times whatever I'm taking the derivative with respect to, to the 1 4th minus one power. Look, all I did is use the power rule here. I didn't have an x here. Now I'm taking the derivative with respect to u of x, with respect to this polynomial expression here. So I could just throw the u of x in here if I like. Actually, let me just do that.