00:01
Okay, so let's get started with part 1.
00:03
Let's find pq.
00:05
This is q minus p.
00:07
So we get 8, negative 3 and 1.
00:15
1.
00:16
Okay, now let's find pr.
00:19
This one is r minus p, so we get 4, 3 minus 2, 1, and negative 2 minus 0, negative 2.
00:33
Okay, now let's find qr.
00:37
This is r minus q, so we get negative 4, 3 minus negative 1, negative 2 minus 1 negative 3.
00:49
Ok, perfect.
00:53
Now part 2 of our exercise, we need to find a unit vector perpendicular to both pq and pr.
01:03
Well, a vector perpendicular to this one and this one is the vector product.
01:10
Product.
01:11
Okay, so the vector product between pq and pr is perpendicular to these two vectors.
01:21
So let's find this vector product.
01:27
Well, the vector product is the determinant of the matrix matrix i, j, k...