Vector Algebra Question 365
Question: If the angle between two vectors $ \mathbf{i}+\mathbf{k} $ and $ \mathbf{i}-\mathbf{j}+a\mathbf{k} $ is $ \pi /3, $ then the value of $ a= $
[MP PET 1997]
Options:
A) 2
B) 4
C) ? 2
D) 0
Show Answer
Answer:
Correct Answer: D
Solution:
- $ \cos \frac{\pi }{3}=\frac{1+a}{\sqrt{2}\sqrt{2+a^{2}}}\Rightarrow a=0 $ .
BETA
