Verified Answer :

These are kinds of
reflections:

Reflection
across x-axis:                        (x,
y) > (x, -y)

Reflection
across y-axis:                        (x,y)
> (-x, y)

Reflection
over origin:                            (x,y) >
(-x,-y)

Reflection
over line y=x:                        (x,y) > (y,x)

Reflection
over line y=-x:                       (x,y)
> (-y,-x)