The topic for week two is integrals. And what we're going to cover in this series of videos, first integration. So this is just the definition of an integral. It's the problem we're trying to solve. And it boils down to basically trying to find the area in between a curve, in between the, a curve representing the graph of a function and the x axis. The second topic, the fundamental theorem of calculus, this gives us a mathematical tool that allows us to answer the question we, we set up in, in part one. In part three, I just discuss some applications of integration. So this is sort of showing the kind of problem you can interpret as an area and then a couple of quick examples of how you can generalize that once I'm allowed to use an integral. Then I'm going to switch to techniques of integration. So, like the differentiation we did in the first week integration is a mathematical operation. It's unfortunately a little bit trickier. So with differentiation, we had a set of rules that you can apply to a function to find its derivative. In integration we have to run that backwards and it's not so clear cut exactly how that's going to work, but there are a lot of sort of rules of thumb that can help you out and so that's what I mean by techniques of integration. Integration by parts, integration by substitution and completing the square are all techniques of integration. So there are tricks that are going to help you find the integral of a function. And then we'll start moving on to some topics we'll need to be able to take derivatives of the Black-Scholes pricing formula. So, in particular, we're going to need to be able to take the derivative of an integral. So, that will be topic number seven, different, differentiating definite integrals. We're also going to look at integrals that have an unbounded region. So, that would be integrating from, say a minus infinity up to a certain value x. We can also look at improper integrals where the function takes an inter, sorry, where the function takes an infinite value, and that will be what we talk about in topic nine, improper integrals two. And then we'll put all of that together and learn how to take the derivative of a function defined to be the improper integral of another function.