Vector Algebra Question 371
Question: The vectors $ \overrightarrow{AB}=3\mathbf{i}+4\mathbf{k}, $ and $ \overrightarrow{AC}=5\mathbf{i}-2\mathbf{j}+4\mathbf{k} $ are the sides of a triangle ABC. The length of the median through A is
[AIEEE 2003]
Options:
A) $ \sqrt{18} $
B) $ \sqrt{72} $
C) $ \sqrt{33} $
D) $ \sqrt{288} $
Show Answer
Answer:
Correct Answer: C
Solution:
- P.V. of $ \overrightarrow{AD}=\frac{(3+5)i+(0-2)j+(4+4)k}{2} $ $ =4\mathbf{i}-\mathbf{j}+4\mathbf{k} $ $ |\overrightarrow{AD}|=\sqrt{16+16+1}=\sqrt{33} $ .
BETA
