Point A is at (1 ,6 ) and point B is at (5 ,-8 ). Point A is rotated pi clockwise about the origin. What are the new coordinates of point A and by how much has the distance between points A and B changed?

1 Answer
Feb 6, 2018

New coordinates of color(brown)(A (-6, -1)

Reduction is distance due to rotation is color(green)( ~~ 1.52 units

Explanation:

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A (1,6), B (5, -8)

From I to III quadrant

A ((1),(6))-> A' ((-6), (-1))

bar(AB) = sqrt((1-5)^2 + (6-(-8))^2 = sqrt212

bar(A'B) = sqrt((-6-5)^2 + (-1+8)^2) = sqrt170

Reduction is distance due to rotation is

color(green)(sqrt212 - sqrt170 ~~ 1.52 units