Vector Algebra Question 294
Question: If the position vectors of A, B, C, D are $ 2,\mathbf{i}+\mathbf{j}, $ $ \mathbf{i}-3,\mathbf{j}, $ $ 3,\mathbf{i}+2,\mathbf{j} $ and $ \mathbf{i}+\lambda \mathbf{j} $ respectively and $ \overrightarrow{AB}||\overrightarrow{CD} $ , then $ \lambda $ will be
[RPET 1988]
Options:
A) 8
B) 6
C) 8
D) 6
Show Answer
Answer:
Correct Answer: B
Solution:
- $ \overrightarrow{AB}=-\mathbf{i}-4\mathbf{j}, $ $ \overrightarrow{CD}=-2\mathbf{i}+(\lambda -2)\mathbf{j} $ $ \because ,\overrightarrow{AB},||\overrightarrow{CD} $ . So , $ \frac{-1}{-2}=\frac{-4}{\lambda -2} $ , $ \lambda -2=-8 $ or $ \lambda =-6. $
BETA
