Question

Find the position vector of a point R which divides the line joining two points P and Q whose position vectors are(2vector a+b) and (vector a-3b)  respectively, externally in the ratio 1 : 2. Also, show that P is the mid-point of the line segment RQ.

Answer 1

The position vector of the point R dividing the join of P and Q externally in the ratio 1 : 2 is

As it is same as position vector of point P, so P is the mid-point of the line segment RQ.