So let's think about this a little bit. So the derivative, let me copy and paste this so I don't have to rewrite it. So copy and paste. So let's think about what the derivative of e to the cosine of x is. E to the cosine of x. So we could view our outer function as e to the something, as e to the something. And the derivative of e to the something with respect to something is just going to be e to that something.