Proof of weaker Baker-Campbell-Hausdorff Formula
71822
Commutator algebra in exponents
33370
Show that the one point compactification of $\mathbb{Q}$ is not Hausdorff
86193
Rigorous proof that $dx dy=r\ dr\ d\theta$
50428
Proof of Neumann Lemma
38354
A result similar to Schwarz lemma
30770
Prove that $C\left(\bigcup_{\alpha\in I} A_\alpha\right)=\bigcap_{\alpha\in I}C\left(A_\alpha\right)$
39583
ii) Show that $u$ is not a real part of the function which analytic on $\mathbb{C} \backslash \lbrace 0 \rbrace$
94469
How to prove that $|HK| = \dfrac{|H| \; |K|}{|H \cap K|}$?
36485
$H_n(X,A) \not \approx \tilde{H}_n(X/A)$
69066
$\epsilon{\rm -}\delta$ proof of the discontinuity of Dirichlet's function
132431
Proving $|f'(z)|\leq\frac{\text{Re}(f(z))}{\text{Re}(z)}$
52014
Showing $(C[0,1], d_1)$ is not a complete metric space
69103
$\limsup$ and cluster points
84181
Is there a cleaner proof of convergence for this almost-telescoping series
120985
Prove that $\mathrm{Res}[f/g,z_0]=\frac{f(z_0)}{g'(z_0)}$
127920
Equivalent Rotation using Baker-Campbell-Hausdorff relation
56143
Proof of a basic $AC_\omega$ equivalence