Points A and B are at (3 ,7 )(3,7) and (4 ,2 )(4,2), respectively. Point A is rotated counterclockwise about the origin by pi π and dilated about point C by a factor of 2 2. If point A is now at point B, what are the coordinates of point C?

1 Answer
May 11, 2018

C=(-10,-16)C=(10,16)

Explanation:

"under a counterclockwise rotation about the origin of "piunder a counterclockwise rotation about the origin of π

• " a point "(x,y)to(-x,-y) a point (x,y)(x,y)

rArrA(3,7)toA'(-3,-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((-3),(-7))-((4),(2))

color(white)(rArrulc)=((-6),(-14))-((4),(2))=((-10),(-16))

rArrC=(-10,-16)