Question

what is the rule for a 90 counterclockwise rotation? (-y, x) (y, -x)

Explanation:

In a 2 - D coordinate system, when a point (x, y) is rotated 90 degrees counter - clockwise about the origin, the x - coordinate of the original point becomes the new y - coordinate and the y - coordinate of the original point becomes the negative of the new x - coordinate.

Answer:

(-y, x)