So let's look up here. So the integral from one to four of f prime, that's that curve right over here. Well, that's going to give this area, but it's going to be the negative of the area because if you just take the integral, it's the area that you could view above the x-axis and below, or if we're thinking in terms of view, above the u-axis and below the function. But this is the other way around. The function is below the horizontal axis here. So this area, which they told us in the problem, the area bounded by the x-axis in the graph of f prime over the interval one, four is 12. So this area over here is 12, but the integral is going to be a negative because once again, our function is below the x-axis.