Points A and B are at (5 ,7 ) and (3 ,6 ), respectively. Point A is rotated counterclockwise about the origin by pi and dilated about point C by a factor of 2 . If point A is now at point B, what are the coordinates of point C?
1 Answer
May 22, 2018
Explanation:
"under a counterclockwise rotation about the origin of "pi
• " a point "(x,y)to(-x,-y)
rArrA(5,7)toA'(-5,-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((-5),(-7))-((3),(6))
color(white)(rArrulc)=((-10),(-14))-((3),(6))=((-13),(-20))
rArrC=(-13,-20)