Question

If a point P(1, 3) is reflected across the line y = 2, what are the coordinates of its reflection image?

(1, 1)
(3, 1)
(–1, 3)
(3, 3)

Answer 1

The point P(1, 3) is one unit up of the line y = 2, a refrection image of P(1, 3) across the line y = 2 will be one unit down of the line y = 2.
Therefore, the coordinate of the refrection image is (1, 1).