Mathematics for IGCSE & O level - Transformations (Section 4 - No. 8)
A point at (3, -2) is rotated 90 degrees counterclockwise about the origin. What are its new coordinates?
(2, 3)
(-2, -3)
(-2, 3)
(2, -3)
解释
90 degrees counterclockwise transforms (x, y) to (-y, x).