Once again, just the fundamental theorem of calculus. And then plus, we're first going to take the derivative of this thing with respect to x squared. And that's going to give you cosine of x squared over x squared. Wherever you saw a t, you replace it with an x squared. And then you're going to multiply that times the derivative of x squared with respect to x. So that's just going to be derivative of x squared with respect to x is just 2x. And we're done.