This is only going to be true when x is equal to two. So step two is looking good. So step three, Olga says f has an inflection point at x equals two. So she's basing this just on the fact that the second derivative is zero when x is equal to two. She's basing this just on the fact that f prime prime of two is equal to zero. Now I have a problem with this because the fact that your second derivative is zero at x equals two, that makes two a nice candidate to check out, but you can't immediately say that we have an inflection point there. Remember, an inflection point is where we go from being concave upwards to concave downwards or concave downwards to concave upwards.