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 (-2, -1) by 270° counter-clockwise about the origin. Give the image coordinates.
Working
- 1R(270°)(x, y) = (y, −x).
- 2x′ = -1 = -1, y′ = −(-2) = 2.