Let's do another one. So here, we want to find the definite integral from seven to four of f of x dx. So we want to go from seven to four. So we want to go from seven to four. Now, you might be tempted to say, okay, well, look, the area between f of x and x is two, so maybe this thing is two. But the key realization is this area only applies when you have the lower bound as the lower bound and the higher value as the higher bound. So the integral from four to seven of f of x dx, this thing, this thing is equal to two.