A line segment has endpoints at #(4 ,0 )# and #(2 ,1 )#. If the line segment is rotated about the origin by #( pi)/2 #, translated vertically by #-8 #, and reflected about the x-axis, what will the line segment's new endpoints be?

1 Answer
Dec 3, 2016

#(4,0)to(0,4)" and " (2,1)to(-1,6)#

Explanation:

Since there are 3 transformations to be performed, label the endpoints A(4 ,0) and B(2 ,1)

First transformation Under a rotation about the origin of #pi/2#

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

Hence A(4 ,0) → A'(0 ,4) and B(2 ,1) → B'(-1 ,2)

Second transformation Under a translation #((0),(-8))#

#"a point " (x,y)to(x,y-8)#

Hence A'(0 ,4) → A''(0 ,-4) and B'(-1 ,2) → B''(-1 ,-6)

Third transformation Under a reflection in the x-axis

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

Hence A''(0 ,-4) → A'''(0 ,4) and B''(-1 ,-6) → B'''(-1 ,6)

Thus after all 3 transformations.

#(4,0)to(0,4)" and " (2,1)to(-1,6)#