Well, it's trying to sign it based on the idea that now our function is below the x-axis. So we could kind of think that we have an area of 2, but it's all below the x-axis in this case. And so it is signed as negative 2. The actual area is 2, but since it's below the x-axis, we get a negative right over here. Now let's do one more interesting one. Let's find the definite integral from 0 to 3 pi over 2 of cosine of x dx. Now, this is just denoting this entire area, going from 0 all the way to 3 pi over 2.