We would have to confirm that our second derivative crosses signs, or switches signs, as we cross that x value. But here we can't find a situation where our second derivative is equal to zero. But we have to remind ourselves that other candidate inflection points are where our second derivative is undefined. And so he can't make this statement without seeing where our second derivative could be undefined. So for example, he could say that g prime prime is undefined, undefined when what? Well, this is going to be undefined when x is equal to zero. X zero to the fifth, cube root of that, that's gonna be zero but then you're dividing by zero.