Question regarding Euler's form
742
How to prove Euler's formula: $e^{i\varphi}=\cos(\varphi) +i\sin(\varphi)$?
11989
$ac\equiv bc \pmod{\!m}\!\!\iff\!\! a\equiv b \pmod{\!\!\frac{m}{(c,m)}}$ [Euclid's Lemma, congruence form]
8311
Is there another proof for Euler–Mascheroni Constant?
82878
Order of cyclic groups and the Euler phi function
29531
A Question On Euler's Proof Of the Basel Problem
145835
Closed form for CRT solution using Euler $\phi\,$ (totient)
157717
What is a mathematical solution to this problem? (Project Euler #106)
96039
Why is $\frac {1\cdot2\cdot3\cdot...\cdot n}{(n+1)(n+2)...(2n)}\le \frac 1 {n+1}$
147317
multiple choice question on number theory
81267
A simple doubt in number theory problem.
129801
Finding a closed form for $\sum^{n}_{k=1} \frac{k}{(k+1)!} $
7755
Question on entire function
132065
Prove sum of $\cos(\pi/11)+\cos(3\pi/11)+...+\cos(9\pi/11)=1/2$ using Euler's formula
39199
closed form for $\binom{n}{0}+\binom{n}{3}+\binom{n}{6}+...+\binom{n}{n}$
86567
Understanding $\sum_{x = 0}^y x = \frac{y(y + 1)}{2}$ in a step of a proof
53426
Proof of a formula involving Euler's totient function: $\varphi (mn) = \varphi (m) \varphi (n) \cdot \frac{d}{\varphi (d)}$
138331
questions about Rudin's summation by parts