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Mathematics
Mathematics
Problem
Calculate
cos
2
θ
\cos 2\theta
cos
2
θ
when
θ
=
30
∘
\theta=30^{\circ}
θ
=
3
0
∘
. a)
3
2
\dfrac{\sqrt{3}}{2}
2
3
b)
1
1
1
c)
1
2
\dfrac{1}{2}
2
1
d)
−
1
2
-\dfrac{1}{2}
−
2
1
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