All of that over the denominator squared. All of that over three y squared minus x squared. Now lucky for us, they want us to evaluate this at a point as opposed to have to do a bunch of algebraic simplification here. So we can say when, let me do it over here. So when, I'll do it right here. When x is equal to negative one and y is equal to one, well, first of all, what's dy dx going to be? The derivative of y with respect to x.