 Now I move on to my vector subtraction example, and in this case I'm using B minus D. And again, we're using the B minus D, which you can't see in this video screen, but which is up at the top of your worksheet. Now if I do this again by components, I'm going to copy and paste in here something I've already written up, and that's going to give me the chance to show you what's going on here once it stops jumping around. B was minus 2 I had, minus 3 J had. Now originally D was plus 4 I had, minus 2 J had, but when I multiply and make it minus D, that becomes minus 4 and plus 2. So I had to change the sign on both the I and the J when I put the minus D in. And then I go ahead and do that math. Now it's not that I'm subtracting these, I've already taken account the minus sign. So I've got minus 2 and minus 4 gives me minus 6 on the I hat side, and minus 3 and minus 2 is going to give me minus 1 on the J hat side. So that's how I look at it in terms of doing the math on the equations. Graphically it gets a little interesting. I'm going to start here by drawing in our B vector. And the B vector is going to go 2 to the right and 3 down. And again let me just make that a little bit of a thicker arrow. When I do that I'm then going to start at this point and follow not along D but along minus D. Now as I do that I'll show you how it relates to D. But the minus D is going to go 1, 2, 3, 4 to the right and 2 up. If it had been D it would have gone 4 to the right and 2 down. But it goes in the exact opposite direction so that's 4 to the left and 2 up. So there's my minus D. And my resultant vector is going to be 1 that starts here and goes over to that point. 1, 2, 3, 4, 5, 6 to the left and 1 down. Sorry it keeps jumping over there. I'll just keep scrolling back over. So graphically this is B and negative D and that gives me the result there. Sometimes we think about this in a slightly different way which is a little bit harder to see where I use B and D and then the diagonal of the parallelogram it makes but that's very hard for introductory students to actually sort of get a picture of it. So instead of taking that approach I wanted to show you and emphasize to you here that it's B and then the negative D vector. Focus on these in terms of looking at the components.