And so any point where your first derivative is equal to zero or it's undefined, it is indeed a critical point. So this step looks good so far. And then step three, h has a relative extremum at x equals two. All right, so she made a big conclusion here. She assumed that because the derivative was zero, that we have a relative extremum. So let's just see if you can even just make that conclusion. 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.