Mathematics for IGCSE & O level - Transformations (Section 6 - No. 6)
When reflecting a point (x, y) across the line y = -x, what happens to the coordinates?
(x, y) becomes (-x, -y)
(x, y) becomes (-y, -x)
(x, y) becomes (y, x)
(x, y) becomes (-y, x)
Explication
Reflecting across y = -x, the point (x,y) becomes (-y, -x).