We essentially, and you can even pattern match up here, and we'll get more intuition of why this is true in future videos. But essentially, everywhere where you see this right over here is an f of t. Everywhere you see a t, replace it with an x, and it becomes an f of x. So this is going to be equal to cosine squared of x over the natural log of x minus the square root of x. You take the derivative of the indefinite integral where the upper boundary is x right over here, it just becomes whatever you were taking the integral of, that as a function instead of t, that is now a function of x. So it can really simplify sometimes taking a derivative. And sometimes you'll see on exams these trick problems where you have this really hairy thing that you take a definite integral of and then take the derivative. And you just have to remember the fundamental theorem of calculus, the thing that ties it all together, connects derivatives and integration, that you can just simplify it by realizing that this is just going to be, instead of a function of lowercase f of t, it's going to be lowercase f of x.