Point A is at (6 ,4 ) and point B is at (-2 ,7 ). 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(brown)("Decrease in distance due to rotation "

color(green)(= vec (AB) - vec(A'B) = 8.54 - 2.24 = 6.3 " units"

Explanation:

![https://www.onlinemath4all.com/http://rotation-transformation.html](https://useruploads.socratic.org/U3wqLZDTKqMygVfW5llb_rotation%20rules.jpg)

A (6,4), B (-2, 7)

"A rotated about origin by " (3pi)/2 " clockwise"

vec (AB) ' sqrt((6+2)^2 + (4-7)^2) = 8.54 " units"

A (6,4) -> A'(-4, 6), " rotated clockwise by " (3pi)/2 " about origin"

vec (A'B) = sqrt((-4+2)^2 + (6-7)^2) = 2.24 " units"

color(brown)("Decrease in distance due to rotation "

color(green)(= vec (AB) - vec(A'B) = 8.54 - 2.24 = 6.3 " units"