Question

Find the position vector of a point R which divides the line joining two points P and Q whose position vectors  i+2j-k and i+j+k  are respectively, in the ration 2:1
(i) internally
(ii) externally

Answer 1

The position vector of point R dividing the line segment joining two points P and Q in the ratio m: n is given by:

(i) The position vector of point R which divides the line joining two points P and Q internally in the ratio 2:1 is given by,

(ii) The position vector of point R which divides the line joining two points P and Q externally in the ratio 2:1 is given by,