Vector Algebra Question 302
Question: The direction cosines of vector $ \mathbf{a}=3\mathbf{i}+4\mathbf{j}+5\mathbf{k} $ in the direction of positive axis of x, is
[MP PET 1991]
Options:
A) $ \pm \frac{3}{\sqrt{50}} $
B) $ \frac{4}{\sqrt{50}} $
C) $ \frac{3}{\sqrt{50}} $
D) $ -\frac{4}{\sqrt{50}} $
Show Answer
Answer:
Correct Answer: C
Solution:
- $ \frac{3}{\sqrt{3^{2}+4^{2}+5^{2}}}=\frac{3}{\sqrt{50}}. $
BETA
