Vector Algebra Question 292
Question: The points with position vectors $ 10,\mathbf{i}+3,\mathbf{j},12,\mathbf{i}-5,\mathbf{j} $ and $ a,\mathbf{i}+11,\mathbf{j} $ are collinear, if $ a= $
[MNR 1992; Kurukshetra CEE 2002]
Options:
A) 8
B) 4
C) 8
D) 12
Show Answer
Answer:
Correct Answer: C
Solution:
- If given points be $ A,B,C $ then $ \overrightarrow{AB}=k(\overrightarrow{BC}) $ or $ 2\mathbf{i}-8\mathbf{j}=k[(a-12)\mathbf{i}+16\mathbf{j}]\Rightarrow k=\frac{-1}{2} $ Also, $ 2=k(a-12)\Rightarrow a=8. $
BETA
