In order to have a relative extremum, your curve is gonna look something like this, and then you would have a relative extremum right over here. And over here, your slope goes from being positive, and then it hits zero, and then it goes to being negative. Or you could have a relative extremum like this. This would be a maximum point. This would be a minimum point right over here. And then in a minimum point, your slope is zero right over there, but right before it, your slope was negative, and it goes to being positive. But you actually have cases where your derivative, your first derivative is zero, but you don't have an extremum.