Q.15 (2) Find the position vector of a point R which divides the line joining two points P and Q whose position vectors are and respectively, in the ratio 2 : 1 externally
As we know
The position vector of the point R which divides the line segment PQ in ratio m:n externally:
Here
position vector os P = =
the position vector of Q =
m:n = 2:1
And Hence