Answer:
a) the x-coordinate changes sign
b) the y-coordinates are unchanged
c) this is a reflection across the y-axis
Explanation:
a)
Each image point is on the same horizontal line as the original. It is as far from the y-axis as the original, but in the opposite direction. Its x-coordinate has changed sign.
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b)
The y-coordinate is the same for each image point as for the original. The y-coordinates have not changed.
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c)
The line of reflection is the perpendicular bisector of the segment joining the original point and its image. In every case, that is the y-axis. The image is a reflection across the y-axis.