Points A and B are at (2 ,7 )(2,7) and (4 ,6 )(4,6), 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 27, 2018

C=(-4,-34/3)C=(4,343)

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(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))-((4),(6))

color(white)(rArr3ulc)=((-8),(-28))-((4),(6))=((-12),(-34))

rArrulc=1/3((-12),(-34))=((-4),(-34/3))

rArrC=(-4,-34/3)