Points A and B are at (9 ,3 )(9,3) and (7 ,8 )(7,8), respectively. Point A is rotated counterclockwise about the origin by pi π 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
Jun 27, 2018
Explanation:
"under a counterclockwise rotation about the origin of "piunder a counterclockwise rotation about the origin of π
• " a point "(x,y)to(-x,-y)∙ a point (x,y)→(−x,−y)
A(9,3)toA'(-9,-3)" where A' is the image of A"
vec(CB)=color(red)(2)vec(CA')
ulb-ulc=2(ula'-ulc)
ulb-ulc=2ula'-2ulc
ulc=2ula'-ulb
color(white)(ulc)=2((-9),(-3))-((7),(8))
color(white)(ulc)=((-18),(-6))-((7),(8))=((-25),(-14))
rArrC=(-25,-14)