A line segment has endpoints at (7 ,4 )(7,4) and (5 ,9)(5,9). If the line segment is rotated about the origin by (pi )/2 π2, translated vertically by 5 5, and reflected about the y-axis, what will the line segment's new endpoints be?

1 Answer
Jun 7, 2017

(-4,-2)" and " (-9,0)(4,2) and (9,0)

Explanation:

Since there are 3 transformations to be performed, label the endpoints.
A(7,4)" and " B(5,9)A(7,4) and B(5,9)

color(blue)"First transformation "First transformation

"Under a rotation about the origin of " pi/2Under a rotation about the origin of π2

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

rArrA(7,4)toA'(-4,7)" and " B(5,9)toB'(-9,5)

color(blue)"Second transformation"

"Under a translation of " ((0),(-5))

"a point " (x,y)to(x,y-5)

rArrA'(-4,7)toA''(-4,2)

"and " B'(-9,5)toB''(-9,0)

color(blue)"Third transformation"

"Under a reflection in the y-axis"

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

rArrA''(-4,2)toA'''(-4,-2)

"and " B''(-9,0)toB'''(-9,0)

"After all 3 transformations"

(7,4)to(-4,-2)" and " (5,9)to(-9,0)