Question

What transformation is represented by the rule (x, y)→(x, −y)(x, y)→(x, −y) ?

reflection across the x-axis

rotation of 90° counterclockwise about the origin

rotation of 180° about the origin

reflection across the y-axis

Answer 1

Each point (x,y) goes to (x, -y)

All the 'y' coordinate values are flipped to negative...