The question is to find the equation of a plane through three points.
P (1,2,-1)
Q (2,3,1)
R (3,-1,2)
vectors
PQ (1,1,2)
RQ (1,-4,1)
PR (2,-3,3)
How come PQ and PR are parallel, is RQ parallel as well? I'm following my textbook and it doesn't mention anything about it.
I can do the work, I'm just curious about RQ.
Edit: Solved.