•Strategy.
–Suppose P represents five points.
V1 transforms P so that first 4 to
canonical position, and fifth to (a,b,c).
– Next, suppose we are given TP,
with T unknown. Find V2 to transform first 4 points of TP to canonical position.
–V2 = V1*T-1. V2P has fifth
point = (a,b,c).
–For this to work, V1,
V2 must be uniquely determined.