Points A and B are at (8 ,5 )(8,5) and (2 ,2 )(2,2), respectively. Point A is rotated counterclockwise about the origin by (3pi)/2 3π2 and dilated about point C by a factor of 3 3. If point A is now at point B, what are the coordinates of point C?
1 Answer
Feb 27, 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(8,5)toA'(5,-8)" where A' is the image of A"
rArrvec(CB)=color(red)(3)vec(CA')
rArrulb-ulc=3(ula'-ulc)
rArrulb-ulc=3ula'-3ulc
rArr2ulc=3ula'-ulb
color(white)(rArr2ulc)=3((5),(-8))-((2),(2))
color(white)(rArr2ulc)=((15),(-24))-((2),(2))=((13),(-26))
rArrulc=1/2((-13),(-26))=((13/2),(-13))
rArrC=(13/2,-13)