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Mathematics
Mathematics
Problem
Let
a
,
b
,
c
\mathbf{a}, \mathbf{b}, \mathbf{c}
a
,
b
,
c
be three vectors of magnitude 1, 1 and 2 respectively. If
a
×
(
a
×
c
)
+
b
=
0
\mathbf{a} \times (\mathbf{a} \times \mathbf{c}) + \mathbf{b} = 0
a
×
(
a
×
c
)
+
b
=
0
, then the acute angle between
a
\mathbf{a}
a
and
c
\mathbf{c}
c
is a.
π
3
\frac{\pi}{3}
3
π
b.
π
4
\frac{\pi}{4}
4
π
c.
π
6
\frac{\pi}{6}
6
π
d. None of these
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