So suppose f is a function continuous at every point of the interval a, b. So let me draw some axes here. So that's my y-axis, and this is my x-axis. So one situation, if this is a, and this is b, f is continuous at every point of the closed interval a and b, so that means it's got to be, for sure, defined at every point as well as being continuous. To be continuous, you have to be defined at every point, and the limit of the function as you approach that point should be equal to the value of the function of that point. And so the function is definitely going to be defined at f of a, so it's definitely going to have an f of a right over here, this right over here is f of a. Maybe f of b is higher, although we can look at different cases.