00:01
Once we're given these vectors, u and v, and we're going to find the cross product and the dot product.
00:05
Do the cross product first.
00:10
U cross v.
00:13
So it's given as...
00:16
Now, one way to do this, there's not the only way.
00:19
You have j and k.
00:21
We've seen some other cool methods, but this is one method that kind of resonates with me.
00:25
You write them out.
00:25
2, 1, 5, 3, negative, 2, 4.
00:31
So you write them like this, and we get i as the determinant of this little matrix here.
00:40
1 -5 -n -2 -4 minus -jay.
00:47
And what we do is you take i, which is in, oopsies.
00:53
You take i, and that gets this matrix.
00:56
And for j, you cross out the j and that column, you get this.
01:00
So you get 2, 5, 3, 4, and you plus k.
01:11
And then to do this one, we cross this out, and we get 2, 1, 3, negative 2.
01:22
Great.
01:23
And now we take the, now we have our vector.
01:27
And then it's going to be our i term...