Question

The coordinates of a quadrilateral are (1, 2), (4, 2), (1, 4), and (4, 4). After a transformation, the new coordinates are (1, −2), (4, −2), (1, −4), and (4, −4). Which transformation occurred?

Answer 1

Reflection across the x-axis bc of the change in y. 

Answer 2

The coordinates of the original quadrilateral are (1, 2), (4, 2), (1, 4), and (4, 4). After transformation, the new coordinates are (1, −2), (4, −2), (1, −4), and (4, −4). Thus, as we can see, the y coordinates of the original points have been multiplied by -1. This happens only when there is a reflection about the x axis.

Thus, the type of transformation in question here is reflection about the x axis.

Please find the attached graph to get a clearer picture of the explanation given here.