Is it true for a reflection on a plane...
To reflect across the:
xy-plane (x,y,z)→(x,y,−z)
xz-plane (x,y,z)→(x,−y,z)
yz-plane (x,y,z)→(−x,y,z)?
Is that true for all planes or just a few particular ones?
Only for the coordinate planes.
Slanted planes produce other results.