Mathematics for IGCSE & O level - Transformations (Section 1 - No. 34)
A shape is rotated 90 degrees clockwise about the origin. What is the effect on a point (x, y)?
(x, -y)
(y, -x)
(-y, x)
(-x, -y)
解释
90 degrees clockwise rotation changes (x, y) to (y, -x).