Q11 of 177 Page 23

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

If P and Q are two points with position vector and then the position vector of mid point A is given by

Let A is the mid point of PQ.

So, position vector of A

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).

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

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

Show that the points are the vertices of a right angled triangle.