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Mathematics
Mathematics
Problem
If
a
\mathbf{a}
a
,
b
\mathbf{b}
b
,
c
\mathbf{c}
c
are non-coplanar unit vectors also
b
\mathbf{b}
b
,
c
\mathbf{c}
c
are non-collinear and
2
a
×
(
b
×
c
)
=
b
+
c
2\mathbf{a} \times (\mathbf{b} \times \mathbf{c}) = \mathbf{b} + \mathbf{c}
2
a
×
(
b
×
c
)
=
b
+
c
, then a. angle between
a
\mathbf{a}
a
and
c
\mathbf{c}
c
is
60
∘
60^\circ
6
0
∘
b. angle between
b
\mathbf{b}
b
and
c
\mathbf{c}
c
is
30
∘
30^\circ
3
0
∘
c. angle between
a
\mathbf{a}
a
and
b
\mathbf{b}
b
is
120
∘
120^\circ
12
0
∘
d.
b
\mathbf{b}
b
is perpendicular to
c
\mathbf{c}
c
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