00:01
On this question, we are asked two things.
00:03
On part a, we were asked to find the dot product.
00:07
And on b, we were asked to find the angle between the two vectors.
00:12
All right.
00:14
For the dot product, u.
00:17
Dot v.
00:18
To find the dot products, you multiply corresponding elements.
00:23
So i would do 2 times 3, and then you add it to 7 times 1.
00:33
So we multiply corresponding elements and then add them together.
00:38
So this is 6 plus 7, which is 13.
00:43
So the dot product between you and v is 13.
00:49
Next on part b, we're asked to find the angle between the two to the nearest degree.
00:57
So for finding the angle, we have the cosine theta, where theta is the angle between them, is equal to u .v over the magnitude of u times the magnitude of v.
01:13
So for the magnitude over here, we take the square root and then it's the first element squared plus the second element squared.
01:26
So i'd have two squared plus seven squared.
01:31
And that's the square root of four plus 49.
01:40
Which is the square root of 53...