Question

Instruction

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Writing a Rule for a Rotation
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What rule describes the rotation about the origin?
C'
(x, y)
4
tated about the
✓
2
A'
B'
(y, -x)
-4
-2
2
(-y, x)
B
A
-2
(-x-y)
(x, y)​

Answer 1

Answer: Choice C. (-x, -y)

Step-by-step explanation:

Focus on one point, such as A = (1,2). Note how it moves to point A ' = (-1, -2). Both x and y coordinates have been flipped from positive to negative. The rule therefore is
`(x,y) \to (-x,-y)`. This describes a 180 degree rotation (either clockwise or counterclockwise, it doesn't matter). Points B and C follow the same idea.

Side note: Lines AA', BB' and CC' all go through the origin (0,0).