Question

If the mirror image of the point P(5, 2) in x-axis is the point Q and the image of Q in y-axis is R. Then the coordinates of R are
(a) (5, –2)
(b) (–5, –2)
(c) (–5, 2)
(d) (2, 5)

Answer 1

Under reflection of a point in the x-axis, the abscissa of the point remains unchanged while the sign of the ordinate is changed. So, the image of the point (x, y) in the x-axis is (x, −y).

So, the image of the point P(5, 2) in x-axis is Q(5, −2).

Now, under reflection of a point in the y-axis, the ordinate of the point remains unchanged while the sign of the abscissa is changed. So, the image of the point (x, y) in the y-axis is (−x, y).

So, the image of the point Q(5, −2) in y-axis is R(−5, −2).

Thus, the co-ordinates of the point R are (−5, −2).

Hence, the correct answer is option (b).