Points A and B are at (5 ,9 ) and (8 ,6 ), respectively. Point A is rotated counterclockwise about the origin by pi and dilated about point C by a factor of 2 . If point A is now at point B, what are the coordinates of point C?

1 Answer
Jul 26, 2018

C=(-18,-24)

Explanation:

"Under a counterclockwise rotation about the origin of "pi

• " a point "(x,y)to(-x,-y)

A(5,9)toA'(-5,-9)" where A' is the image of A"

vec(CB)=color(red)2vec(CA')

ulb-ulc=2(ula'-ulc)

ulb-ulc=2ula'-2ulc

ulc=2ula'-ulb

color(white)(ulc)=2((-5),(-9))-((8),(6))

color(white)(ulc)=((-10),(-18))-((8),(6))=((-18),(-24))

rArrC=(-18,-24)