Is there a closed form representation of the sum $$\sum_{k=1}^x \cos\left(\frac{n\pi}{k}\right)$$ where $n$ and $x$ are integers? If not possible, is there a representation that uses special functions?
2026-03-30 10:11:48.1774865508
Finding Closed Form Representation of A Sum of Trigonometric Functions
66 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in TRIGONOMETRY
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