A line segment has endpoints at (7 ,9 ) and (5 ,2). If the line segment is rotated about the origin by pi , translated vertically by -4 , and reflected about the x-axis, what will the line segment's new endpoints be?

1 Answer
Apr 7, 2017

(-7,13)" and " (-5,6)

Explanation:

Since there are 3 transformations to be performed, label the endpoints A(7 ,9) and B(5 ,2)

color(blue)"first transformation" " Under a rotation about origin of " pi

"a point " (x,y)to(-x,-y)

"Hence "A(7,9)toA'(-7,-9)

"and " B(5,2)toB'(-5,-2)

color(blue)"Second transformation" " Under a translation " ((0),(-4))

"a point " (x,y)to(x,y-4)

"Hence " A'(-7,-9)toA''(-7,-13)

"and " B'(-5,-2)toB''(-5,-6)

color(blue)"third transformation"" Under a reflection in the x-axis"

"a point " (x,y)to(x,-y)

"Hence " A''(-7,-13)toA'''(-7,13)

"and " B''(-5,-6)toB'''(-5,6)

"After all 3 transformations"

(7,9)to(-7,13)" and " (5,2)to(-5,6)