So that that equals 1 over the square root of x. Delta x is 0, so we can ignore that. We can take the limit all the way to 0. And then this is, of course, just a square root of x here plus the square root of x. And that equals 1 over 2 square root of x. And that equals 1 half x to the negative 1 half. So we just proved that x to the 1 half power, the derivative of it, is 1 half x to the negative 1 half. And so it is consistent with the general property that the derivative of x to the n is equal to nx to the n minus 1.