Question

What are the coordinates of the image of point (−1, 5) after a counterclockwise rotation of 90º about the origin?

Answer 1

-5,0 would be the correct answer

Answer 2

`(-5,-1)`

Explanation:

We have been given the coordinates of a point and we are asked to find the coordinates of he point after a counterclockwise rotation of 90º about the origin.

We know that after rotating a point 90 degree counter-clockwise about the origin, the x and y-coordinates changes places with each other and x-coordinate of new point becomes the negative of y-coordinate.

`(x,y)\rightarrow (-y,x)`

Applying the rotation rule the coordinates of new point would be:

`(-1,5)\rightarrow (-5,-1)`

Therefore, the required coordinates of the given point after a counterclockwise rotation of 90º about the origin would be
`(-5,-1)`.