00:01
Okay, we've been given these two vectors and we'd like to find the angle between them.
00:04
We're going to use a simple formula.
00:05
Cos of our angle is equal to the dot product between our two vectors.
00:10
We'll call them u and v over the length of u times by the length of v.
00:16
So let's work out these three things and plug it back into our formula.
00:19
U.
00:19
Dot v will be minus 4 times minus 6, so that's going to be positive 24.
00:25
And then we'll have 6 times 8, which should be 48.
00:30
So adding those two together, you'll get 60, blah, blah, blah, so 72 on the top.
00:37
For our length of view, you're going to have to do the square root of u .dop product with itself.
00:43
So you'll have the square root of 16 plus 36, which is, i have to check on my calculator, 16 plus 36, 52, which is equivalent to 2 root 13, if you'd like to simplify.
01:00
Then we need to find the length of v.
01:04
So that's v, square root of v...