Vector Algebra Question 391
Question: The value of $ \lambda $ for which the vectors $ 2\lambda \mathbf{i}+\mathbf{j}-\mathbf{k} $ and $ 2\mathbf{j}+\mathbf{k} $ are perpendicular, is
[MP PET 1992]
Options:
A) None
B) ? 1
C) 1
D) Any value
Show Answer
Answer:
Correct Answer: A
Solution:
- Since $ (2\lambda \mathbf{i}+\mathbf{j}-\mathbf{k}),.,(2\mathbf{j}+\mathbf{k})=1 $ for every $ \lambda , $ therefore the vectors will not be perpendicular for any $ \lambda . $