Video: Determining the Coordinates of a Point after Its Reflection over the 𝑥-Axis

Video Transcript

Scarlet and Mason are trying to find the coordinates of the image four, nine after a reflection over the 𝑥-axis. Scarlet’s answer was four, negative nine while Mason’s answer was negative four, nine. Which of them is correct?

Here’s what we know about coordinates. We have our 𝑥-axis and our 𝑦-axis. Quadrant one represents positive, positive. Quadrant two has coordinates with a negative 𝑥 and a positive 𝑦. In quadrant three, both the 𝑥- and 𝑦-axis values are negative. And in quadrant four, we have a positive 𝑥 value and a negative 𝑦 value.

Our image is a positive and a positive and would fall in the first quadrant. If this image is reflected over the 𝑥-axis, it will be reflected down into the fourth quadrant. It would be positive four, negative nine. And that is reflected in Scarlet’s answer.

Scarlet answered correctly by saying that the reflected image would be located at four, negative nine.