Points A and B are at (4 ,3 ) and (5 ,2 ), respectively. Point A is rotated counterclockwise about the origin by (3pi)/2 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
Feb 28, 2018
Explanation:
"under a counterclockwise rotation about the origin of "(3pi)/2
• " a point "(x,y)to(y,-x)
rArrA(4,3)toA'(3,-4)" 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),(-4))-((5),(2))
color(white)(rArrulc)=((6),(-8))-((5),(2))=((1),(-10))
rArrC=(1,-10)