So let's start with an example. Let's say we want to evaluate the definite integral going from negative four to negative two of f of x, d of x, plus the definite integral going from negative two to zero of f of x, dx. Pause this video and see if you can evaluate this entire expression. So this first part of our expression, the definite integral from negative four to negative two of f of x, dx, we're going from x equals negative four to x equals negative two. And so this would evaluate as this area between our curve and our x-axis, but it would be the negative of that area because our curve is below the x-axis. And we could try to estimate it based on the information they've given us, but they haven't given us exactly that value. But we also need to figure out this right over here.