How to find the exact value of $ \cos(36^\circ) $?
44715
Exact value for $\cos 36°$
17082
Number of real roots of $2 \cos\left(\frac{x^2+x}{6}\right)=2^x+2^{-x}$
39752
Is there a limit of $\cos(n!)$?
94382
Calculate the degree of the extension $[\mathbb{Q}(\cos(\frac{2\pi}{p})):\mathbb{Q}]$
127004
Extreme of $\cos A\cos B\cos C$ in a triangle without calculus.
95633
Help with this trigonometry problem
99328
Value of $\sin (2^\circ)\cdot \sin (4^\circ)\cdot \sin (6^\circ)\cdots \sin (90^\circ) $
81750
$4 \sin 72^\circ \sin 36^\circ = \sqrt 5$
122705
Solution of trigonometric equation $0 = x\cos(x)+2$
39461
What is the solution of $\cos(x)=x$?
79983
Finding the exact area of a circle?
76490
Proving that $\cos(\arcsin(x))=\sqrt{1-x^2}$
127001
Evaluate $\lim_{x\to \infty} \cos (\sqrt {x+1})-\cos (\sqrt x)$
155148
Why is $\sin 30^\circ=\frac{1}{2}$
38975
Find the value of $\textrm{cosec}^2\left(\frac\pi7\right) +\textrm{cosec}^2\left(\frac{2\pi}7\right)+\textrm{cosec}^2\left(\frac{4\pi}7\right)$
109171
How to evaluate this trigonometric limit?
54587
Finding value (Trigo Series)