But you might be saying, well, okay, look, maybe u substitution could be at play here because I have this kind of crazy expression, x to the third times the natural log of two, but what's the derivative of that? Well, that's going to be three x squared times the natural log of two, or three times the natural log of two times x squared. Well, that's just a constant times x squared. We already have a x squared here, and so maybe we can engineer this a little bit to have the constant there as well. So let's think about that. So if we made this, if we defined this as u, so if we said u is equal to x to the third times the natural log of two, what is du going to be? Well, du is going to be, it's going to be, well, natural log of two is just a constant, so it's going to be three x squared times the natural log of two.