00:01
Well, they tell you exactly what to do in this problem.
00:03
One thing they tell you to do is to find the midpoint as well as the slope, because it titles says that it's a perpendicular.
00:14
All right, perpendicular in front.
00:19
Perp is finding the slope.
00:21
So as you look at the problem, where they give you the ordered pairs negative 2, negative 1, and then the other ordered pair of 4 -3, 1, 2, 3, 1, 2, 3, 4.
00:36
1, 2, 3.
00:39
Well, if you're trying to find the midpoint, what you want to do is the midpoint formula, which i don't even memorize.
00:46
What i tell students is just to think of the average of the two numbers.
00:51
Because if you want the halfway point between negative 2 and 4, then you have to add the numbers and divide by 2.
00:57
You have to do the same thing with the ys, add the numbers and divide by 2.
01:02
So if i were to connect these two dots and find the midpoint, it makes sense to me that the midpoint would be negative 2 plus 4 divided by 2, as well as negative 1 plus 3 divided by 2.
01:24
Well, if you actually do that, negative 2 plus 4 is 2 divided by 2, and negative 1 plus 3 is also 2 divided by 2.
01:32
So it makes sense that this ordered pair is at 1 -1.
01:37
Now the other thing is you better find the slope of what do they call those, ab, ab.
01:46
So the slope of ab is, well, you can just do the slope formula...