Point A is at (-5 ,9 ) and point B is at (-3 ,4 ). Point A is rotated (3pi)/2 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
Mar 29, 2018

color(indigo)("Increase in distance due to the rotation of A is "

color(purple)(= vec(A'B) - vec(AB) = 6.08 - 5.39 = 0.69 " units"

Explanation:

A(-5,9), B (-3,4)

vec(AB) = sqrt((-5+3)^2 + (9-4)^2) = 5.39 " units"

Point A rotated (3pi)/2 clockwise about the origin.

![https://www.onlinemath4all.com/http://rotation-transformation.html](https://useruploads.socratic.org/bZDPsMSfSx29x75Lcx0p_rotation%20rules.jpg)

A(-5, 9) -> A'(-9, 5)

vec(A'B) sqrt((-9+3)^2 + (5-4)^2) = 6.08 " units

color(indigo)("Increase in distance due to the rotation of A is "

color(purple)(= vec(A'B) - vec(AB) = 6.08 - 5.39 = 0.69 " units"