So these are going to be equivalent. Let's say, let me just draw that scenario, so let me draw a scenario where it's my x axis, that is my y axis, and let's say I have, let's say I have a function that looks like that, so that is y is equal to g of x, and let's say that this right over here is a, and this right over here is b, and let's say that this area right over here is equal to five. Well, if I were to ask you what is the definite integral from a to b of g of x dx, what do you think it is going to be? Well, you might be tempted to say, hey, well, it's just the area again between my curve and the x axis. You might be tempted to say, hey, this is just going to be equal to five, but you have to be very careful, because if you're looking at the area above your curve and below your x axis versus below your curve and above the x axis, this definite integral is actually going to be the negative of the area. Now, we'll see later on why this will work out nicely with a whole set of integration properties, but if you want to get some intuition for it, let's just think about velocity versus time graphs. So if I, in my horizontal axis, that is time.