Rotation of a point
Guided practice — solve each problem, check, then generate a fresh one.
Formula to apply
R(90°) (x, y) = (−y, x)
Problem
Rotate the point (3, 3) by 90° counter-clockwise about the origin. Give the image coordinates.
Working
- 1R(90°)(x, y) = (−y, x).
- 2x′ = −(3) = -3, y′ = 3 = 3.