00:01
We're going to show that the three points, 4 -2, 75, and 9 -4 lie on a right line.
00:10
So let's take a look and see where those points would be if we were to graph them on the coordinate plane.
00:15
So 4 -2 would be roughly about right here.
00:18
So we're going to 4 -2.
00:20
7 -5 then would be like, let's just put it right here.
00:26
And 9 -4 is going to be further out, 9 and up 4, so like right there.
00:32
Okay.
00:36
And what we're asking is that we're saying it's a right line.
00:40
That means this needs to be a right angle right there.
00:44
So to determine that that's a right angle, what we can do is look at the slopes of each piece of the line.
00:52
What is the slope of this piece and what is the slope of this piece.
00:56
So let's take a look and we're going to call this piece one and this is piece two so that we can refer to them as.
01:05
As the slope.
01:06
So let's find the slope of the first one.
01:09
Remember to find the slope, we can call the slope m.
01:13
We take y2 minus y1 over x2 minus x1.
01:18
So for slope 1, my points are 4 -2 and 7 -5.
01:26
So if i call this x1, y -1, x2, y -2, it does not matter which ones are your ones or your twos.
01:34
What matters is that if this right here, the four is x -1, my two has to be y1.
01:38
It can't be y2.
01:40
I can't mix and match my ones and two is within the same order pair...