ok... back in school after a 3-week faculty strike. I'm pretty sure I got this wrong: specifics aren't important. the question was to find a point on a given plane closest to a point A. What I did was find a point B on the plane, and do proj(n)(AB) n being a normal to the plane. ... when I look in my textbook the answer to a question like this is perp(n)(BA). Are they both right, or did I do it wrong? ... I mean, it makes sense to me that a projection of AB onto n would land in the same place, no?