Identify the following surfaces:
ii) r.u=mlrl for -1[itex]\leq[/itex]m[itex]\leq[/itex]1
where k, L, m are fixed scalars and u is a fixed unit vector.
The Attempt at a Solution
The first one is in the same form as the equation of a plane, but u is not necessarily the normal, so I'm confused. For the second one, I have no idea.