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Mathematics
Mathematics
Problem
Let
A
A
A
and
B
B
B
denote the statements
A
:
cos
α
+
cos
β
+
cos
γ
=
0
A: \cos \alpha + \cos \beta + \cos \gamma = 0
A
:
cos
α
+
cos
β
+
cos
γ
=
0
B
:
sin
α
+
sin
β
+
sin
γ
=
0
B: \sin \alpha + \sin \beta + \sin \gamma = 0
B
:
sin
α
+
sin
β
+
sin
γ
=
0
If
cos
(
β
−
γ
)
+
cos
(
γ
−
α
)
+
cos
(
α
−
β
)
=
−
3
2
\cos(\beta - \gamma) + \cos(\gamma - \alpha) + \cos(\alpha - \beta) = -\frac{3}{2}
cos
(
β
−
γ
)
+
cos
(
γ
−
α
)
+
cos
(
α
−
β
)
=
−
2
3
, then a.
A
A
A
is true and
B
B
B
is false b.
A
A
A
is false and
B
B
B
is true c. Both
A
A
A
and
B
B
B
are true d. Both
A
A
A
and
B
B
B
are false
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