Points A and B are at (6 ,5 )(6,5) and (7 ,8 )(7,8), respectively. Point A is rotated counterclockwise about the origin by pi/2 π2 and dilated about point C by a factor of 2 2. If point A is now at point B, what are the coordinates of point C?
1 Answer
Mar 21, 2018
Explanation:
"under a counterclockwise rotation about the origin of "pi/2under a counterclockwise rotation about the origin of π2
• " a point "(x,y)to(-y,x)∙ a point (x,y)→(−y,x)
rArrA(6,5)toA'(-5,6)" 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),(6))-((7),(8))
color(white)(rArrulc)=((-10),(12))-((7),(8))=((-17),(4))
rArrC=(-17,4)