And we could call this u of x. And then, whatever we get for u of x, we raise that to the 4th power. So the way that we would take the derivative, we would take the derivative of this, you could view it as the outer function with respect to u of x, and then multiply that times the derivative of u with respect to x. So let's do that. So what this is going to be, this is going to be equal to, so we're gonna take our outside function, which I'm highlighting in green now, so where I take something to the 1 4th, I'm gonna take the derivative of that with respect to the inside, with respect to u of x. Well, I'm just gonna use the power rule here. I'm just gonna bring that 1 4th out front.