00:01
So we're going to start with an arbitrary point, which i called c, and the designation x, comma, y.
00:13
And i pick c, 2, 1.
00:17
And first we're going to reflect that across the line y equals x, which is shown here in dashed.
00:23
And the rule for that is reverse the x and the y coordinates.
00:29
So our c prime will be one common.
00:34
Two.
00:36
Then we have to do a counterclockwise, 270 degree rotation about the origin.
00:45
And the rule for that is to take our original y coordinate will become our x coordinate and our the opposite of our original x coordinate will become our new y coordinate.
01:10
So that yields c prime of 2 comma negative 1.
01:17
Now, we need to go directly from point c to point c double prime.
01:31
And when i look at the coordinates, we see that the x coordinate stays the same and the y coordinate, the sign is changed.
01:41
So i can write a general rule for the composition of these two individual transformations.
01:48
As x comma y becomes x comma minus y...