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  • 1 Morsbacher Straße 10, 51545 Waldbröl, Germany
  • 2 The Hong Kong Polytechnic University, Hunghom, Hong Kong
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Abstract

We prove: For all natural numbers n and real numbers x ∈ [0, π] we have 548130585k=1n(1)k+1(sin((2k1)x)2k1+sin(2kx)2k).

The sign of equality holds if and only if n = 2 and x = 4π/5.

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