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

Jul 27, 2018

$\left(- 2 , - 4\right) \text{ and } \left(- 2 , - 5\right)$

Explanation:

$\text{Since there are 3 transformations to be performed label}$
$\text{the endpoints}$

$A = \left(1 , 2\right) \text{ and } B = \left(2 , 2\right)$

$\textcolor{b l u e}{\text{first transformation}}$

$\text{under a rotation about the origin of } \frac{3 \pi}{2}$

• " a point "(x,y)to(y,-x)

$A \left(1 , 2\right) \to A ' \left(2 , - 1\right)$

$B \left(2 , 2\right) \to B ' \left(2 , - 2\right)$

$\textcolor{b l u e}{\text{second transformation}}$

$\text{under a vertical translation } \left(\begin{matrix}0 \\ - 3\end{matrix}\right)$

• " a point "(x,y)to(x,y-3)

$A ' \left(2 , - 1\right) \to A ' ' \left(2 , - 4\right)$

$B ' \left(2 , - 2\right) \to B ' ' \left(2 , - 5\right)$

$\textcolor{b l u e}{\text{third transformation}}$

$\text{under a reflection in the y-axis}$

• " a point "(x,y)to(-x,y)

$A ' ' \left(2 , - 4\right) \to A ' ' ' \left(- 2 , - 4\right)$

$B ' ' \left(2 , - 5\right) \to B ' ' ' \left(- 2 , - 5\right)$

$\text{After all 3 transformations}$

$\left(1 , 2\right) \to \left(- 2 , - 4\right) \text{ and } \left(2 , 2\right) \to \left(- 2 , - 5\right)$