density of $\mathbb{Q}$ and $\mathbb{R}$ in $\mathbb{R}^2$
16517
Arcwise connected part of $\mathbb R^2$
111898
Is $\{ (e^{2\pi i a n},e^{2\pi i b n }) : n \in \mathbb{Z} \}$ dense in the torus, where $a,b$ irrationals such that $a/b$ irrational?
27188
Bijection between $\mathbb{R}$ and $\mathbb{R}/\mathbb{Q}$
53244
Prove that $p \in \mathbb{R}[x]$ can be represented as a sum of squares of polynomials from $\mathbb{R}[x]$
106625
Strength of the statement "$\mathbb R$ has a Hamel basis over $\mathbb Q$"
158011
$C_c^{\infty}(\mathbb R^n)$ is dense in $W^{k,p}(\mathbb R^n)$
48162
Is the subset $[0, \sqrt2] ∩\mathbb{Q} ⊂ \mathbb{Q}$ closed, bounded, compact?
44704
familly of Radially open sets in $\mathbb{R}^2$
4381
Proof that the set of irrational numbers is dense in reals
78733
Finding the density for $\min\{X, Y\}$
83967
Why is $|\Psi|^2$ the probability density?
60787
Natural density of solvable quintics
154076
How to show this property of $\mathbb{RP}^{n}$.
110885
Does there exists a continuous surjection from $\mathbb{R}$ to $\mathbb{R}^2$?
26497
Take $\mathbb{R}$ as a vector space over $\mathbb{Q}$, then a basis for $\mathbb{R}$, then $|B|=2^{\aleph_0}$
57839
Real analysis: density and continuity
2575
Showing that $\mathbb{R}$ is connected