The function might take on higher values later on. And to identify this as a local minimum point, the function might take on lower values later on. But we saw, even if we don't have the graph in front of us, if we're able to take the derivative of the function, we might, or even if we're not able to take the derivative of the function, we might be able to identify these points as minimum or maximum. The way that we did it, we said, OK, what are the critical points for this function? Well, critical points are where the function's derivative is either undefined or 0. This is the function's derivative. It is 0 here and here.