Find a vector equation r(t) for the line segment that joins P and Q. P = (1, 2, 3), Q = (5,-1,2) Hint:User(t) = (1 t)P + tQ, where we think of the ordered triples P and Q as vectors (so vector operations such as scalar multiplication apply). Note when t= 0 this gives P, and when t = 1 this gives Q.