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题目求证:sum from k=1 to n cos[(a+2(k-1)π)/n]=0(n≥3,n∈N).这是一道经典的三角恒等式,有不少文章谈及它的证明方法.笔者收集、整理,得到了四种构造性的证明方法.本文一一介绍给大家.以供参考.
Proof: sum from k=1 to n cos[(a+2(k-1)π)/n]=0(n≥3,n∈N). This is a classic trigonometric identity. There are many articles. Speaking of its proof method, the author has collected and arranged four constructive proof methods. This article is introduced to everyone for reference.