And if I were to just simplify this a little bit, in fact, you see it very clearly, these two things are equivalent. This term is exactly equivalent to this term, the way it's written. And then this is exactly, if you multiply three times x to the sixth, sine of x squared cosine of x. So the nice thing about math, if we're doing things that make logical sense, we should get to the same end point. But the point here is that there's multiple strategies. You could use the chain rule first and then the product rule or you could use the product rule first and then the chain rule. In this case, you could debate which one is faster.