Question

Reflection of a point about x-axis, followed by a counter-clockwise rotation of 900 , is equivalent to reflection about the line ?

Answer 1

Answer:

reflection of a point about counter clockwise rotation of 900 is equivaleny to reflection about the line and rotate anti- clockwise.

Answer 2

Reflection of a point about x-axis, followed by a counter-clockwise rotation of 900, is equivalent to reflection about the origin.

• When a point is reflected about the x-axis, the sign of the y co-ordinate changes.
• When a point is rotated in the counter-clockwise direction by 90°, the quadrant of the point changes. The point shifts to the adjacent quadrant. This changes the sign of the x co-ordinate as well.
• Since the sign of both the co-ordinates is changing, it can be said that the point is reflected about the origin.