Vector Algebra Question 220
Question: A, B, C, D, E are five coplanar points, then $ \overrightarrow{DA}+\overrightarrow{DB}+\overrightarrow{DC}+\overrightarrow{AE}+\overrightarrow{BE}+\overrightarrow{CE} $ is equal to
[RPET 1999]
Options:
A) $ \overrightarrow{DE} $
B) $ 3,\overrightarrow{DE} $
C) $ 2,\overrightarrow{DE} $
D) $ 4,\overrightarrow{ED} $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ A,,B,,C,,D,,E $ are five co-planar points. $ \overrightarrow{DA}+\overrightarrow{DB}+\overrightarrow{DC}+\overrightarrow{AE}+\overrightarrow{BE}+\overrightarrow{CE} $ = $ (\overrightarrow{DA}+\overrightarrow{AE})+(\overrightarrow{DB}+\overrightarrow{BE})+(\overrightarrow{DC}+\overrightarrow{CE}) $ = $ \overrightarrow{DE}+\overrightarrow{DE}+\overrightarrow{DE} $ = $ 3\overrightarrow{DE}. $
BETA
