00:02
We are given two points.
00:05
These points are negative 16 .8, 12 .3, and 5 .6, 4 .9.
00:15
In part a, we are asked to plot these points.
00:20
Notice that the x coordinates of the points range from negative 16 .8 up to 5 .6, and the y coordinates from 4 .9 to 12 .3.
00:32
So i'm going to draw the x coordinate, the x -axis, ranging from a nice whole number, let's say negative 20 to positive 10.
01:02
And our y -axis, i'll simply only draw from 0 to 15.
01:13
If you want to, you can draw a more detailed graph, but i'm just going to draw a sketch here.
01:32
So to plot these points, well, we have the point negative 16 .8, 12 .3 lies on the intersections of the lines x equals negative 16 .8 and y equals 12 .3.
01:54
Now, negative 16 .8 is slightly less than negative 15, and 12 .3 is less than 15.
02:06
Our first point is located somewhere around here.
02:19
Now our next point, 5 .6, 4 .9, is likewise located approximately here.
02:29
5 .6 is a little over 5.
02:32
And 4 .9 is a little bit under 5, which is 1 3rd of 15.
02:43
So we have a plot of our two points.
02:47
Next, in part b, we're asked to find the distance between these points.
02:56
First, let's estimate the distance using our graph from part a.
03:01
So if i draw a line between these two points, a straight line, we want to find the length of this straight line.
03:14
We can approximate this length by recalling the triangle inequality from geometry, which says that the sum of two sides, of the lengths of two sides of a triangle, is always less than, is always, sorry, greater than the length of the third side of the triangle.
03:42
So, for example, if i draw a triangle like this, where the legs are parallel to the x and y axes, this is a right triangle here, then we have that the legs are going to have lengths.
03:58
Let's see, this is going to be 12 .3 minus 4 .9, which i'll just approximate as 12 minus 5 .5.
04:08
Or 7, and this leg is going to have a length of 5 .6 minus negative 16 .7, which i'll approximate as 5 minus 7, negative 17, or 5 plus 17, which is 22.
04:31
We know this third side is going to have a length less than 7 plus 22, some of the other lengths, which is 29.
04:42
So we should expect the length of this third side, and therefore the distance between these two points to be less than 29...