identity for finding value of $\pi$
24311
Proving $\frac{\sin x}{x} =\left(1-\frac{x^2}{\pi^2}\right)\left(1-\frac{x^2}{2^2\pi^2}\right) \left(1-\frac{x^2}{3^2\pi^2}\right)\cdots$
46353
Proof that $\cos(\pi/3)=1/2$
44400
$e^{2\pi i x} = (e^{2\pi i})^x$: What happens if x is rational?
95145
Does $\exp(2ir\pi)$ equal $1$? What's wrong?
22767
How to prove $3^\pi>\pi^3$ using algebra or geometry?
83359
Complex number identity by trigonometry
24022
Compute $\int _0 ^{2\pi} (\sum_{n=1}^\infty \frac {\cos(nx)}{2^n})^2 dx$
48881
Verification the integral identity $\int_0^\pi \ln(1+\alpha\cos(x))dx=\pi\ln\left(\frac{1+\sqrt{1-\alpha^2}}{2}\right)$.
139625
Proof of a Fibonacci identity
21003
Comparing $\pi^e$ and $e^\pi$ without calculating them
98741
Finding $\int_{0}^{\frac{\pi}{4}} \frac{\tan \theta - \tan^3 \theta}{\ln \tan \theta}$
133186
Understanding the "$\pi$" of a rotating disk
143093
Determining k: $\int_{6}^{16} \frac{dx}{\sqrt{x^3 + 7x^2 + 8x - 16}} = \frac{\pi}{k}$
7134
Confusion related to calculation of pi
118374
Is there a proof that $\pi$ is an irrational number?
43659
Why is $\pi$ so close to $3$?
100936
What is the sum of this series: $\frac{2}{\pi}\sum_{k=1}^{\infty}\frac{(-1)^{k-1}}{2k-1}$