Question

Which of the following are the coordinates of point F prime , the image of point F, after a rotation of 90° about the origin?

1.(3,0)
2.(-3,0)
3.(0,-3)
4.(0,3)

Answer 1

He correct answer is (-3,0)

Answer 2

There are 2 possibilities:

if F is rotated 90° about the origin in the clockwise (negative) direction, the image is the point F'(3, 0), as shown with the red line segments.

if F is rotated 90° about the origin in the counterclockwise (positive) direction, the image is the point F'(-3, 0), as shown with the green line segments.

both 1 and 2 are possible.


Remark: A rotation of point F, it the movement of F in a circle with center O and with radius OF.