Mathematics for IGCSE & O level - Transformations (Section 1 - No. 8)
If an object is reflected over the line y = -x, how do the coordinates change?
(x, y) becomes (-x, -y)
(x, y) becomes (y, x)
(x, y) becomes (-y, -x)
(x, y) becomes (-y, x)
解释
Reflection over y = -x swaps the coordinates and negates them (x, y) -> (-y, -x).