0 is not an inflection point. Let's see if positive and negative 3 are inflection points. If you study this equation, let me write our... Actually, I just want to be clear. I've just been using the numerator of the second derivative. The whole second derivative is this thing right here, but I've been ignoring the denominator, because the denominator is always positive. If we're trying to understand whether things are positive or negative, we just really have to determine whether the numerator is positive or negative, because this expression right here is always positive. It's something to the second power.