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}}.$

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Directions: In the following questions, the Assertions (A) and Reason(s) (R) have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion (A): It is necessary to find objective function value at every point in the feasible region to find optimum value of the objective function.
Reason(R): For the constrains $2\text{x}+3\text{y}\leq6,5\text{x}+3\text{y}\leq15,\text{x}\geq0$ and $\text{y}\geq0$ cornner points of the feasible region are (0, 2), (0, 0) and (3, 0).
  1. Both A and R are true and R is the correct explanation of A
  2. Both A and R are true but R is NOT the correct explanation of A
  3. A is true but R is false.
  4. A is false but R is true.