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Mathematics
Mathematics
Problem
Exact value of
cos
20
∘
+
2
sin
2
55
∘
−
2
sin
65
∘
\cos 20^\circ + 2 \sin^2 55^\circ - \sqrt{2} \sin 65^\circ
cos
2
0
∘
+
2
sin
2
5
5
∘
−
2
sin
6
5
∘
is - (A) 1 (B)
1
2
\frac{1}{\sqrt{2}}
2
1
(C)
2
\sqrt{2}
2
(D) zero
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