How to write $\pi_1$
9462
Command/macro name cannot include numbers and symbols
39266
Show that $\tan {\pi \over 8} = \sqrt 2 - 1$
17188
Simplify $\cos(n \pi)$ and $\sin(n \pi)$ when n is an integer
104828
Show that $\cot \frac{\pi}{2m}\cot \frac{2\pi}{2m}\cot \frac{3\pi}{2m}...\cot \frac{(m-1)\pi}{2m}=1$
120953
Show that, $2\arctan\left(\frac{1}{3}\right)+2\arcsin\left(\frac{1}{5\sqrt2}\right)-\arctan\left(\frac{1}{7}\right)=\frac{\pi}{4}$
124209
How is $\ln(-1) = i\pi$?
105973
how do we know the BBP formula for $\pi$ is valid?
154305
Let $\pi$ denote a prime element in $\mathbb Z[i], \pi \notin \mathbb Z, i \mathbb Z$. Prove that $N(\pi)=2$ or $N(\pi)=p$, $p \equiv 1 \pmod 4$
105177
Gosper's unusual formula connecting $e$ and $\pi$
11391
Series that converge to $\pi$ quickly
142835
Proving :$\arctan(1)+\arctan(2)+ \arctan(3)=\pi$
116014
Write $\frac {1}{1+z^2}$ as a power series centered at $z_0=1$
95145
Does $\exp(2ir\pi)$ equal $1$? What's wrong?
132928
Digits of $\pi$ forming primes?
25181
Simple numerical methods for calculating the digits of $\pi$
130686
How is $3\pi-10$ element of $[-\pi/2,\pi/2]$?
127365
Question on showing a bijection between $\pi_1(X,x_0)$ and $[S^1, X]$ when X is path connected.