00:01
Okay, i want to find the angle between the groups.
00:05
For that, i use the scalar product formula, which is u.
00:09
Dot v, is the length of u, the length of v, cosine the angle between the vectors.
00:20
I want to find theta, this equation here in this formula.
00:24
Well, u, i'll write as 14, 5, that notation, v, minus 12, and 6, the length of u, pythagoras, the square root of 14 squared plus 5 squared.
00:47
And then the root of a length of v, the square root of minus 12.
00:58
And again, minus 12 squared plus 6 squared, cosine, theta.
01:08
That's the first step.
01:10
Again, the values for u and v.
01:15
On the left, i work out this scale of product.
01:19
So i do 14 times minus 12.
01:23
So 14 times minus 12 is negative 168.
01:29
And here, 5 times 6 plus 30.
01:35
Equal to square root of 14 squared plus 5 squared is 221...