Points A and B are at (2 ,7 ) and (8 ,6 ), respectively. Point A is rotated counterclockwise about the origin by pi and dilated about point C by a factor of 4 . If point A is now at point B, what are the coordinates of point C?

1 Answer
Feb 22, 2018

C=(-16/3,-34/3)

Explanation:

"under a counterclockwise rotation about the origin of "pi

• " a point "(x,y)to(-x,-y)

rArrA(2,7)toA'(-2,-7)" 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),(-7))-((8),(6))

color(white)(rArr3ulc)=((-8),(-28))-((8),(6))=((-16),(-34))

rArrulc=1/3((-16),(-34))=((-16/3),(-34/3))

rArrC=(-16/3,-34/3)