Question

andrews rotation maps point \\(m(9, -1)\\) to \\(m(-9, 1)\\). which describes the rotation?

\\(180^\circ\\) rotation
\\(270^\circ\\) clockwise rotation
\\(90^\circ\\) counterclockwise rotation
\\(90^\circ\\) clockwise rotation

Explanation:

Identify the coordinates of the pre-image and image

Using the Rotation Rules knowledge point

$$ M(x, y) = M(9, -1) $$

$$ M'(x', y') = M'(-9, 1) $$

Determine the coordinate transformation rule

Using the Rotation Rules knowledge point

$$ (x, y) ightarrow (-x, -y) $$

Identify the rotation corresponding to the rule

Using the Rotation Rules knowledge point

$$ R_{180^\circ}(x, y) = (-x, -y) $$

Answer:

• (A) 180° rotation (Correct answer)
• (B) 270° clockwise rotation
• (C) 90° counterclockwise rotation
• (D) 90° clockwise rotation