Vector Algebra Question 26
Question: The projection of the vector $ i-2j+k $ on the vector $ 4i-4j+7k $ is
[RPET 1990; MNR 1980; MP PET 2002; UPSEAT 2002; Pb. CET 2004]
Options:
A) $ \frac{5\sqrt{6}}{10} $
B) $ \frac{19}{9} $
C) $ \frac{9}{19} $
D) $ \frac{\sqrt{6}}{19} $
Show Answer
Answer:
Correct Answer: B
Solution:
- Projection of a on b $ =,|\mathbf{a}|,\cos \theta =|\mathbf{a}|\frac{\mathbf{a},\mathbf{.},\mathbf{b}}{|\mathbf{a}||\mathbf{b}|}=\frac{\mathbf{a},\mathbf{.},\mathbf{b}}{|\mathbf{b}|} $ $ =\frac{4+8+7}{\sqrt{16+16+49}}=\frac{19}{\sqrt{81}}=\frac{19}{9}. $
BETA
