Answers from top to bottom:
(0,-6)
(-1,0)
(-1,-6)
(0,0)
Explanation:
The rule you use is [tex](x,y) \to (-x,-y)[/tex] when it comes to 180 degree rotations (either clockwise or anticlockwise/counterclockwise). So we flip the signs of the x and y coordinates. Any point on an axis will stay on the same axis. The origin is the intersection of the two axes, so this point does not move at all. We call this point fixed or stationary. The fixed point is one where every point rotates around it.
