Points A and B are at (7 ,3 )(7,3) and (3 ,2 )(3,2), respectively. Point A is rotated counterclockwise about the origin by (3pi)/2 3π2 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
May 18, 2018
Explanation:
"under a counterclockwise rotation about the origin of "(3pi)/2under a counterclockwise rotation about the origin of 3π2
• " a point "(x,y)to(y,-x)∙ a point (x,y)→(y,−x)
rArrA(7,3)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))-((3),(2))
color(white)(rArrulc)=((6),(-14))-((3),(2))=((3),(-16))
rArrC=(3,-16)