AP EAMCET202120 Aug 2021Morning ShiftMathematicsThree Dimensional GeometryActual
If the direction cosines of two lines are 2 3 , 2 3 , 1 3 and 5 13 , 12 13 , 0 , then identify the direction ratios of a line which is bisecting one of the angle between them.
Options
- A⟨ 40 ,   60 ,   13 ⟩
- B⟨ 41 ,   60 ,   10 ⟩
- C⟨ 41 ,   62 ,   13 ⟩
- D⟨ 1 ,   2 ,   3 ⟩
Correct answer
C. ⟨ 41 ,   62 ,   13 ⟩
Step-by-step solution
Given, the direction cosines of two lines are 2 3 ,   2 3 ,   1 3 and 5 13 ,   12 13 ,   0 . We know that, the direction ratios of the line bisecting the angle between the lines whose direction cosines are l 1 ,   m 1 ,   n 1 and l 2 ,   m 2 ,   n 2 are proportional to ⟨ l 1 + l 2 ,   m 1 + m 2 ,   n 1 + n 2 ⟩ . Hence, the required direction ratios are proportional to ⟨ 2 3 + 5 13 ,   2 3 + 12 13 ,   1 3 + 0 ⟩ = ⟨ 41 39 ,