Proving the Beltrami-Laplacian of $S^2$.
92746
$\Delta \mathbf n = -2 \mathbf n$ on the Euclidean sphere
119139
Show that antipodal points remain antipodal under any isometry of $S^2$
130045
Show that $l^2$ is a Hilbert space
65562
Proving the inequality $\arctan\frac{\pi}{2}\ge1$
152442
An annulus in $\mathbb R^2$ is path connected
137640
Proof that $\sum_{1}^{\infty} \frac{1}{n^2} <2$
123478
Generalized Poincaré Inequality on H1 proof.
118049
Show that $\mathbb{R}^{\mathbb{R}} = U_{e} \oplus U_{o}$
20192
Prove that: $(f(x))^{2} + (f'(x))^{2} \leqslant \max(a,b)$ where $(a,b) \in \mathbb{R}^2$
26658
A proof for $\nabla |u|^p = p\ \text{sgn}(u)|u|^{p-1}\nabla u$.
124688
Question about a metric on $\mathbb{R}^2$
65357
Fractional Laplacian on the torus
132063
locally on $S$ one of the coordinates is a $C^∞$ function of the other coordinate. Show that $S$ is a submanifold of $R^2$
119579
$S^2 \times S^2$ is diffeomophic to $G_2(\mathbb{R}^4)$
135059
Prove that the unit circle, $S^1:=\{(x,y)\in \mathbb{R}^2: x^2+y^2=1\}$, Is a one-dimensional manifold
141194
Prove that $\frac{(n-2)s^2}{\sigma^2}\sim \chi^{2}_{n-2}$
89468
Space Sobolev $W^{m,p}$ complete