What transformation is represented by the rule [tex](x, y) \rightarrow (y, -x)[/tex]?

A. rotation of [tex]180^{\circ}[/tex] about the origin
B. reflection across the [tex]y[/tex]-axis
C. rotation of [tex]90^{\circ}[/tex] clockwise about the origin
D. reflection across the [tex]x[/tex]-axis



Answer :

To determine the transformation represented by the rule [tex]\((x, y) \rightarrow (y, -x)\)[/tex], we need to analyze the changes to the coordinates [tex]\((x, y)\)[/tex].

1. Initial Point Analysis: Start with a point [tex]\((x, y)\)[/tex].

2. Transformation Application: Apply the transformation [tex]\((x, y) \rightarrow (y, -x)\)[/tex]. This changes the original coordinates [tex]\((x, y)\)[/tex] to [tex]\((y, -x)\)[/tex].

3. Effect of Transformation:
- For a point on the x-axis, [tex]\((x, 0)\)[/tex], the transformation changes this to [tex]\((0, -x)\)[/tex].
- For a point on the y-axis, [tex]\((0, y)\)[/tex], the transformation changes this to [tex]\((y, 0)\)[/tex].

4. Interpretation:
- This specific change, where each point [tex]\((x, y)\)[/tex] is mapped to [tex]\((y, -x)\)[/tex], indicates that there is a rotation involved.
- The point [tex]\((x, y)\)[/tex] after transformation lies 90 degrees clockwise from its initial position on the coordinate plane.

5. Conclusion:
- The rule [tex]\((x, y) \rightarrow (y, -x)\)[/tex] corresponds to a rotation of 90 degrees clockwise about the origin.

Therefore, the transformation represented by the rule [tex]\((x, y) \rightarrow (y, -x)\)[/tex] is a rotation of 90 degrees clockwise about the origin.