Question

Find a vector equation and parametric equations for the line segment that joins P to Q.
P(1,-1,6), Q(6,5,1)

Answer 1

\[r(t)=(1-t)r0+tr\] why is (1-t) used? that confuses me.

Answer 2

Just notice that at t=0, the vector points at r0, and at t= 1, the vector points at r.