Question
Find the position vector of a point R which divides the line joining two points 
externally in the ratio 1 :2. Also, show that P is the middle point of the line segment RQ.
Solution
The position vector of R which divides the join of P 
externally in the ratio 1 : 2 i.e. internally in the ratio 1 : 2 is
Mid-point of RQ is
which is position vector of P.
Hence the result.
externally in the ratio 1 : 2 i.e. internally in the ratio 1 : 2 is Mid-point of RQ is
which is position vector of P.
Hence the result.
