Q10 of 177 Page 23

Find the position vector of a point R which divides the line segment joining points and in the ratio 2 : 1.

(i) Internally


(ii) Externally

By using section formula,


(1) Internally


Position vectors of P and Q are given as


and



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,




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,


(2)Externally





More from this chapter

All 177 →
8

If the vertices A, B, C of a triangle ABC are the points with position vectors respectively, what are the vectors determined by its sides? Find the length of these vectors.

 9

Find the vector from the origin O to the centroid of the triangle whose vertices are (1, -1, 2), (2, 1, 3) and (-1, 2, -1).

 11

Find the position vector of the mid-point of the vector joining the points and

12

Find the unit vector in the direction of vector where P and Q are the points (1, 2, 3) and (4, 5, 6).