And now we can just directly take the limit as it approaches 0. We can just set delta x is equal to 0. That's what it's approaching. 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.