Well, the derivative with respect to x of the square root of y, here we want to apply the chain rule, so let me make it clear. So we have plus this x, plus this x, plus whatever business this is. And I'm going to do this in blue. Well, it's going to be the derivative of the square root of something with respect to that something. Well, the derivative of the square root of something with respect to that something or the derivative of something to the 1 half with respect to that something It's going to be 1 half times that something to the negative 1 half power. Once again, this right over here is the derivative of the square root of y with respect to y. We've seen this multiple times.