And I know that was kind of a long way of saying it. I'm trying to explain the chain rule at the same time. But once you get the hang of it, you're just going to say, all right, well let me take the derivative of the outside of something to the third power with respect to the inside. Let me just treat that cosine of x like as if it was an x. Well that's going to be, the second I did that, that's going to be three cosine squared of x. So that's that part and that part. And then let me take the derivative of the inside with respect to x.