We know the position function, but not the acceleration function. But luckily, we also know that the acceleration function is the derivative with respect to time of the velocity function, which is the derivative with respect to time of the position function. So the acceleration function is the second derivative of this, and then we have to just find its average value over this interval. So let's do that. Let's take the derivative of this twice. And before we do it, let me just even rewrite this so it's going to be a little bit easier to differentiate it. So if we just take each of these two terms of the numerator and divide them by t squared, we're going to get t to the third divided by t squared is just t, and then two divided by t squared, we could write that as plus two t to the negative two power.