Points A and B are at (2 ,4 )(2,4) and (3 ,5 )(3,5), 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
Feb 2, 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(2,4)toA'(-4,2)" 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((-4),(2))-((3),(5))
color(white)(rArrulc)=((-8),(4))-((3),(5))=((-11),(-1))
rArrC=(-11,-1)