Points A and B are at (3 ,7 ) and (4 ,2 ), 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 11, 2018
Explanation:
"under a counterclockwise rotation about the origin of "pi
• " a point "(x,y)to(-x,-y)
rArrA(3,7)toA'(-3,-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((-3),(-7))-((4),(2))
color(white)(rArrulc)=((-6),(-14))-((4),(2))=((-10),(-16))
rArrC=(-10,-16)