To determine the mapping for a 270-degree counterclockwise rotation, we can analyze the effect of this rotation on the coordinates (x, y):
- A 90-degree counterclockwise rotation transforms (x, y) to (-y, x).
- A 180-degree counterclockwise rotation transforms (x, y) to (-x, -y).
- A 270-degree counterclockwise rotation is equivalent to a 90-degree clockwise rotation, which transforms (x, y) to (y, -x).
From your options, the correct mapping corresponding to a 270-degree counterclockwise rotation is:
\((x,y) \rightarrow (y, -x)\)
So, the answer is:
\((x,y) \rightarrow (y, -x)\) (the third option).