A line segment has endpoints at (5 ,9 )(5,9) and (8 ,7 )(8,7). If the line segment is rotated about the origin by ( pi)/2 π2, translated vertically by -2 2, and reflected about the y-axis, what will the line segment's new endpoints be?

1 Answer
Aug 20, 2016

(5,9)to(9,3)" and " (8,7)to(7,6)(5,9)(9,3) and (8,7)(7,6)

Explanation:

Since there are 3 transformations to be performed here, name the endpoints A(5 , 9) and B(8 ,7) so that we can 'track' the points after each transformation.

First transformation Under a rotation about the origin of pi/2π2

a point (x ,y) → (-y ,x)

hence A(5 ,9) → A'(-9 ,5) and B(8 ,7) → B'(-7 ,8)

Second transformation Under a translation of ((0),(-2))

a point (x ,y) → (x , y-2)

hence A'(-9 ,5) → A''(-9 ,3) and B'(-7 ,8) → B''(-7 ,6)

Third transformation Under a reflection in the y-axis

a point (x ,y) → (-x ,y)

hence A''(-9 ,3) → A'''(9 ,3) and B''(-7 ,6) → B'''(7 ,6)

Thus after all 3 transformations.

(5,9)to(9,3)" and " (8,7)to(7,6)