Three Dimensional Geometry Question 66
Question: If a straight line in space is equally inclined to the co-ordinate axes, the cosine of its angle of inclination to any one of the axes is
[MP PET 1992]
Options:
A) $ \frac{1}{3} $
B) $ \frac{1}{2} $
C) $ \frac{1}{\sqrt{3}} $
D) $ \frac{1}{\sqrt{2}} $
Show Answer
Answer:
Correct Answer: C
Solution:
Here, $ \cos \alpha =\cos \beta =\cos \gamma $
$ \therefore $ $ 3,{{\cos }^{2}}\alpha =1\Rightarrow \alpha ={{\cos }^{-1}}( \pm \frac{1}{\sqrt{3}} ) $ .
BETA
