Points A and B are at (2 ,7 ) and (4 ,6 ), respectively. Point A is rotated counterclockwise about the origin by pi and dilated about point C by a factor of 3 . If point A is now at point B, what are the coordinates of point C?

1 Answer
Mar 21, 2018

C=(-5,-27/2)

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)(3)vec(CA')

rArrulb-ulc=3(ula'-ulc)

rArrulb-ulc=3ula'-3ulc

rArr2ulc=3ula'-ulb

color(white)(rArr2ulc)=3((-2),(-7))-((4),(6))

color(white)(rArr2ulc)=((-6),(-21))-((4),(6))=((-10),(-27))

rArrulc=1/2((-10),(-27))=((-5),(-27/2))

rArrC=(-5,-27/2)