Question

Find the position vector of a point R which divides the line joining the two points P and Q whose vectors i + 2j – k and -i + j + k in the ratio 2:1

1. internally and
2. externally.

Answer 1

\(\overline {OP}\) = i + 2j - k, \(\overline {OQ}\) = -i + j + k

Let R be the position vector of the dividing point,
1.

2.