Question
P and Q are two points with position vectors 3$\overrightarrow{\text{a}}$ - 2$\overrightarrow{\text{b}}$ and $\overrightarrow{\text{a}} + \overrightarrow{\text{b}}$respectively. Write the position vector of a point R which divides the line segment PQ in the ratio 2:1 externally.

Answer

If $\overrightarrow{\text{r}}$is the position vector of R then by section formula
$\overrightarrow{\text{r}} = \frac{2(\overrightarrow{\text{a}} + \overrightarrow{\text{b}} )-1.(3\overrightarrow{\text{a}} - 2 \overrightarrow{\text{b}})}{2-1}$

$ = \frac{2\overrightarrow{\text{a}}+ 2\overrightarrow{\text{b}} - 3\overrightarrow{\text{a}} + 2 \overrightarrow{\text{b}}}{1} = 4 \overrightarrow{\text{b}} - \overrightarrow{\text{a}}.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free