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20
Math Prize 2019 Problem 20
Math Prize 2019 Problem 20
Source:
October 15, 2019
Math Prize for Girls
Problem Statement
Evaluate the infinite product
∏
k
=
2
∞
(
1
−
4
sin
2
π
3
⋅
2
k
)
.
\prod_{k = 2}^{\infty} \left( 1 - 4 \sin^2 \frac{\pi}{3\cdot 2^{k}} \right) .
k
=
2
∏
∞
(
1
−
4
sin
2
3
⋅
2
k
π
)
.
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