Question

The rule
results in which of the following rigid motions?
A
.

reflection across the y-axis

B.

reflection across the line y = x

C.

90° clockwise rotation about the origin

D.

180° counterclockwise rotation about the origin

Answer 1

I don't see the rule you mean — can you paste it?

Meanwhile, here are the standard coordinate rules so you can match yours to the right choice:

- Reflection across the y-axis: (x, y) → (−x, y)
- (1,0) → (−1,0), (0,1) → (0,1)

- Reflection across the line y = x: (x, y) → (y, x)
- (1,0) → (0,1), (0,1) → (1,0)

- 90° clockwise rotation about the origin: (x, y) → (y, −x)
- (1,0) → (0,−1), (0,1) → (1,0)

- 180° rotation (either direction) about the origin: (x, y) → (−x, −y)
- (1,0) → (−1,0), (0,1) → (0,−1)

If you paste the rule (for example an image or a mapping like (x,y)→(y,−x)), I’ll pick which option (A–D) it matches.