A line segment has endpoints at (1 ,2 )(1,2) and (9 ,3 )(9,3). If the line segment is rotated about the origin by ( 3 pi)/2 3π2, translated horizontally by 2 2, and reflected about the x-axis, what will the line segment's new endpoints be?

2 Answers
Jul 19, 2018

color(brown)("After all 3 transformations " color(orange)((1, 2)to(4, 1)" and "(9, 3)to(5, 9)After all 3 transformations (1,2)(4,1) and (9,3)(5,9)

Explanation:

"since there are 3 transformations to be performed"since there are 3 transformations to be performed
"label the endpoints"label the endpoints

A(1, 2)" and "B(9, 3)A(1,2) and B(9,3)

color(indigo)"transformation of rotation about the origin of "(3pi) / 2transformation of rotation about the origin of 3π2

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

rArrA(1, 2)toA'(2, -1)

rArrB(9, 3)toB'(3, -9)

color(indigo)"next transformation under a horizontal translation " ((2),(0))

• " a point "(x,y)to(x + 2, y)

rArrA'(2, -1) to A''(4, -1)

rArrB'(3, -9) to B''(5, -9)

color(indigo)"last transformation under a reflection in the x -axis"

• " a point "(x,y)to(x, -y)

rArrA''(4, -1)toA'''(4, 1)

rArrB''(5, -9)toB'''(5, 9)

color(brown)("After all 3 transformations " color(orange)((1, 2)to(4, 1)" and "(9, 3)to(5, 9)

Jul 19, 2018

(4,1)" and "(5,9)

Explanation:

"Since there are 3 transformations to be performed label"
"the endpoints"

A=(1,2)" and "B=(9,3)

color(blue)"first transformation"

"under a rotation about the origin of "(3pi)/2

• " a point "(x,y)to(y,-x)

A(1,2)toA'(2,-1)

B(9,3)toB'(3,-9)

color(blue)"second transformation"

"under a horizontal translation "((2),(0))

• " a point "(x,y)to(x+2,y)

A'(2,-1)toA''(4,-1)

B'(3,-9)toB''(5,-9)

color(blue)"third transformation"

"under a reflection in the x-axis"

• " a point "(x,y)to(x,-y)

A''(4,-1)toA'''(4,1)

B''(5,-9)toB'''(5,9)

"After all 3 transformations"

(1,2)to(4,1)" and "(9,3)to(5,9)