00:01
We need to determine if the points are parallel, perpendicular, or neither.
00:05
So we're first going to find the slope of a, b, and our slope is change in y over change in x.
00:14
So we have 3 minus 1 over negative 2 minus 1.
00:20
So that's 2 over negative 3.
00:23
And then we're going to find the slope of cd.
00:27
And we have 2 minus a negative 1 over 6 over 4.
00:31
So that's 3 over 2.
00:35
So they're negative reciprocals.
00:37
So the first one is perpendicular.
00:40
And we do the second one.
00:41
So the slope of ab, 0 minus 5, 5 minus 0.
00:47
That equals negative 1.
00:48
And the slope of cd is 1 minus 2, 4 minus 3.
00:55
That's negative 1 over 1, which is just negative 1.
01:00
So those are parallel.
01:03
And the next set, we do 5 minus 3, 4 minus a negative 2.
01:13
I don't think that's a negative 2.
01:15
I think it's just 2.
01:17
So that's 2 over 2, so that's positive 1.
01:21
And then cd is 0 minus 1.
01:25
No, 0 minus 3.
01:27
3.
01:28
1 minus 0.
01:30
So that's negative 3.
01:32
So this is neither.
01:33
Because they're not the same and they're not negative reciprocals of each other.
01:37
So then we do the next set, ab.
01:40
So 5 minus 0, 4 minus 0.
01:44
So it's 5 over 4.
01:46
C .d, we got negative 4 minus 3, 5 minus 0.
01:51
That's negative 7 over 5...