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Mathematics
Mathematics
Problem
Find the exact value of
cos
2
75
∘
\cos^2 75^{\circ}
cos
2
7
5
∘
. a)
2
+
3
4
\dfrac{2+\sqrt{3}}{4}
4
2
+
3
b)
2
−
3
4
\dfrac{2-\sqrt{3}}{4}
4
2
−
3
c)
6
−
2
4
\dfrac{\sqrt6-\sqrt2}{4}
4
6
−
2
d)
4
+
6
−
2
8
\dfrac{4+\sqrt6-\sqrt2}{8}
8
4
+
6
−
2
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