Reflections and Symmetry

Reflections and Symmetry basically refer to the "mirror" movement of points. 

Reflection About the $x$-axis

If the original point is $(x,y)$, the new point is $(x, -y)$.

Reflection About the $y$-axis

If the original point is $(x,y)$, the new point is $(-x, y)$.

Reflection About the Origin

If the original point is $(x,y)$, the new point is $(-x, -y)$.