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1973 IMO Shortlist
15
Prove the identity on sines
Prove the identity on sines
Source:
September 22, 2010
trigonometry
algebra
polynomial
Trigonometric Identities
IMO Shortlist
Problem Statement
Prove that for all
n
∈
N
n \in \mathbb N
n
∈
N
the following is true:
2
n
∏
k
=
1
n
sin
k
π
2
n
+
1
=
2
n
+
1
2^n \prod_{k=1}^n \sin \frac{k \pi}{2n+1} = \sqrt{2n+1}
2
n
k
=
1
∏
n
sin
2
n
+
1
kπ
=
2
n
+
1
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