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 MATHEMATICS
438
Example 10 Find the vector joining the points P(2, 3, 0) and Q(– 1, – 2, – 4) directed
from P to Q Solution Since the vector is to be directed from P to Q, clearly P is the initial point
and Q is the terminal point So, the required vector joining P and Q is the vector PQ
uuur ,
given by
PQ
uuur  =
ˆ
ˆ
ˆ
( 1
2)
( 2
3)
( 4
0)
i
j
k
− −
+ − −
+ − −
i e