>> When we first started talking about complex numbers, remember that we began by defining an imaginary unit I, and I was very simply the square root of negative 1. And it opened up a whole new room of mathematical treasures for us. Well here, we're gonna kinda do the same thing except our dilemma at this point, rather than our dilemma being one of not being able to take the square roots of negative numbers which led us into the complex world to begin with, our dilemma now is to have some reality for complex numbers. That is, we can't, at this point, put complex number on to a coordinate plane. But if we make a very simple definition, we can do that. Here's what we'll do. We'll take a coordinate plane and we'll define the horizontal axis as the real axis and the vertical axis as the imaginary axis and that's all we need to do in order to find a point corresponding with the complex number like 5 plus 3I. Now remember that in this complex form, we have a real part and an imaginary part. So--and that correspond well with our real axis and our imaginary axis, and here's how it works. It's that on the real axis we are going to go a distance of 5 and on the imaginary axis a distance of 3 and it corresponds exactly as it would if we were dealing with real numbers. So, it's 1, 2, 3, 4, 5 and then up 1, 2, 3 for this point. Now this is the point then that is 5 plus 3I and it is the point in coordinate form, 5,3 like this as we might expect using real numbers. But now, then think about it in complex form. Here, it's really 5 plus 3I.