It's a correct application of the quotient rule. It looks like Tom is correctly simplifying. So the derivative of x to the 1 1⁄2 is 1 1⁄2 x to the negative 1 1⁄2, so that looks right. Derivative of x to the fourth is four x to the third, so that looks right. All of this looks algebraically right. And let's see, when you simplify this, so let's see, x to the negative 1 1⁄2 times x to the fourth is indeed x to, well, that's going to be x to the, oh, this correlates, so this simplifies to that, which looks correct, and that simplifies to that, which looks correct. We're just using exponent properties there.