Well, that's just going to be one, right? The derivative of x with respect to x is one. The derivative of negative one with respect to x is zero. So we could say times one here if we like, or we could just not write that because it doesn't change the value. And so let's evaluate that when x is equal to negative one. So f prime of negative one is equal to, I could just write this as negative, all right, like this way, negative one over negative one minus one squared. And so this is going to be negative two down here.