5 Show that each of the given three vectors is a unit vector:
1
1
1
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
(2
3
6 ), 
(3
6
2 ),  
(6
2
3 )
7
7
7
i
j
k
i
j
k
i
j
k
+
+
−
+
+
−
Also, show that they are mutually perpendicular to each other © NCERT
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 MATHEMATICS
448
6 Find |
|  and |
|
a
rb
r
, if (
) (
)
8  and | | 8|
|
a
b
a
b
a
b
+
⋅
−
=
=
r
r
r
r
r
r