What I have here in yellow is the graph of y equals f of x. Then here in this mauve color, I've graphed y is equal to the derivative of f, is f prime of x. And then here in blue, I've graphed y is equal to the second derivative of our function. So this is the derivative of this, of the first derivative right over there. And we've already seen examples of how can we identify minimum and maximum points. Obviously, if we have the graph in front of us, it's not hard for a human brain to identify this as a local maximum point. The function might take on higher values later on.