# A line segment with endpoints at (1 , -2 ) and (1, -4 ) is rotated clockwise by pi/2. What are the new endpoints of the line segment?

Nov 20, 2016

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

#### Explanation:

I am assuming a rotation about the origin.

Under a clockwise rotation about the origin of $\frac{\pi}{2}$

$\text{a point } \left(x , y\right) \to \left(y , - x\right)$

$\Rightarrow \left(1 , - 2\right) \to \left(- 2 , - 1\right)$

and $\left(1 , - 4\right) \to \left(- 4 , - 1\right)$