Question

The direction cosines of two rays $\overrightarrow{AB}$ and $\overrightarrow{AC}$ are $\left( \frac{1}{2},\frac{1}{2},-1 \right)$ and $\left( \frac{2}{7},\frac{-3}{7},\frac{6}{7} \right).$ The direction ratios of one of the bisectors of angle $\left( \overrightarrow{AB},\overrightarrow{AC} \right)$ are

• A. $(13,\,-5,\,\,4)$
• B. $(13,\,5,\,\,-5)$
• C. $(13,\,5,4)$
• D. $None\, of\, these$

Answer 1

Answer: (D)

$None\, of\, these$

Answer 2

In this question we are given direction ratios of one ray and direction cosines of other ray and called as direction cosines of both which is wrong.