To determine the function mapping for a 90-degree counterclockwise rotation about the origin, we can analyze how the coordinates of a point \((x, y)\) change.
When a point \((x, y)\) is rotated 90 degrees counterclockwise, it moves to the point \((-y, x)\). Thus, the correct mapping for a 90-degree counterclockwise rotation is:
\[ (x, y) \rightarrow (-y, x) \]
Now, let's review the provided options:
- Option 1: \((x, y) \rightarrow (y, -x)\)
- Option 2: \((x, y) \rightarrow (-y, x)\)
- Option 3: \((x, y) \rightarrow (-x, -y)\)
- Option 4: \((x, y) \rightarrow (y, x)\)
The correct answer is:
Option 2: (x, y) → (-y, x)
Therefore, the mapping for a 90-degree counterclockwise rotation is option #2.