Points A and B are at (5 ,7 ) and (3 ,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
May 22, 2018

C=(-13,-20)

Explanation:

"under a counterclockwise rotation about the origin of "pi

• " a point "(x,y)to(-x,-y)

rArrA(5,7)toA'(-5,-7)" where A' is the image of A"

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

rArrulb-ulc=2(ula'-ulc)

rArrulb-ulc=2ula'-2ulc

rArrulc=2ula'-ulb

color(white)(rArrulc)=2((-5),(-7))-((3),(6))

color(white)(rArrulc)=((-10),(-14))-((3),(6))=((-13),(-20))

rArrC=(-13,-20)