We could just treat sine of x like it's kind of an x. And it would have been just 2x. But instead, it's a sine of x. So we say 2 sine of x times the derivative of sine of x with respect to x. Well, that's more straightforward, a little bit more intuitive. The derivative of sine of x with respect to x, we've seen multiple times, is cosine of x. So times cosine of x.