Point A is at (-9 ,-1 ) and point B is at (3 ,-4 ). 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 22, 2018

Decrease in distance due to clockwise rotation by pi is

color(blue)(d = 4.5591

Explanation:

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Given A (-9,-1), B(3,-4)

Rotated about origin by pi, clockwise.

vec(AB) = sqrt((-9-3)^2 + (-1+4)^2) = 12.3693

A((-9),(-1))-> A’((9),(1))

vec(A’B) = sqrt((9-3)^2 + (1+4)^2) = 7.8102

Decrease in distance due to clockwise rotation by pi is

d = 12.3693 - 7.8102 = 4.5591