New posts in Trigonometric Series

$\cos^2(\frac{\pi}{101})+\cos^2(\frac{2\pi}{101})+\cos^2(\frac{3\pi}{101})+...+\cos^2(\frac{100\pi}{101})=?$

Relationship Between Sine as a Series and Sine in Triangles

Closed form for $\prod\limits_{l=1}^\infty \cos\frac{x}{3^l}$

A Sine and Inverse Sine integral

How do you find the value of $\sum_{r=0}^{44} \tan^2(2r+1)$?

What is the sum over a shifted sinc function?

Prove $ \cos\left(\frac{2\pi}{5}\right) + \cos\left(\frac{4\pi}{5}\right) + \cos\left(\frac{6\pi}{5}\right)+ \cos\left(\frac{8\pi}{5}\right) = -1 $

Proof of $\sum_{n=1}^{\infty}\frac1{n^3}\frac{\sinh\pi n\sqrt2-\sin\pi n\sqrt2}{{\cosh\pi n\sqrt2}-\cos\pi n\sqrt2}=\frac{\pi^3}{18\sqrt2}$

Infinite Series $\sum\limits_{n=1}^{\infty}\frac{1}{4^n\cos^2\frac{x}{2^n}}$

Convergence of series of solutions to $\tan(x)=x$ and $\tan(\sqrt(x)) = x$