Points A and B are at (2 ,9 )(2,9) and (8 ,6 )(8,6), respectively. Point A is rotated counterclockwise about the origin by pi π and dilated about point C by a factor of 4 4. If point A is now at point B, what are the coordinates of point C?

1 Answer
Feb 5, 2018

C=(-16/3,-14)C=(163,14)

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)(xy)

rArrA(2,9)toA'(-2,-9)" where A' is the image of A"

rArrvec(CB)=color(red)(4)vec(CA')

rArrulb-ulc=4(ula'-ulc)

rArrulb-ulc=4ula'-4ulc

rArr3ulc=4ula'-ulb

color(white)(rArr3ulc)=4((-2),(-9))-((8),(6))

color(white)(rArr3ulc)=((-8),(-36))-((8),(6))=((-16),(-42))

rArrulc=1/3((-16),(-42))=((-16/3),(-14))

rArrC=(-16/3,-14)