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Grigor Hakobyan's user avatar
Grigor Hakobyan's user avatar
Grigor Hakobyan's user avatar
Grigor Hakobyan
  • Member for 3 years, 3 months
  • Last seen this week
  • Yerevan, Armenia
11 votes
3 answers
635 views

Can rationals be approximated by increasingly large-denominator rationals?

5 votes
1 answer
99 views

Is there a name for this topology?

4 votes
1 answer
277 views

Proving every Cauchy sequence in $\mathbb{R}$ is convergent

4 votes
1 answer
104 views

Analytic $f: \mathbb{D} \to \mathbb{D}$, $f(0)=0$, and $f$ has five zeros in $\overline{\frac{1}{2}\mathbb{D}}$

4 votes
1 answer
61 views

Finding $\int_\Gamma \frac{z f'(z)}{f(z)} \, dz$ over a given contour [duplicate]

3 votes
2 answers
72 views

Expand $(1-z)^{-m}$ for $m \in \mathbb{N}$ in powers of $z$

3 votes
1 answer
57 views

If $E \in \mathcal{A}$ satisfies $\mu(E)>0$, then there exists $F \subset E, F \in \mathcal{A}$ with $0 < \mu(F) < \infty$

3 votes
2 answers
604 views

Any class of a nonempty $X$ generates a base for a topology on $X$.

3 votes
5 answers
307 views

Compute the limit of $\displaystyle\lim_{n \to \infty} \int_0^1 \frac{e^{-nt}}{\sqrt{t}} \, dt$

3 votes
1 answer
215 views

Invertibility Regarding Inner Product Spaces

3 votes
1 answer
247 views

Is the union of the intersection the same as the intersection of the union?

3 votes
2 answers
755 views

Prove that a set is infinite if and only if it is equipotent to a proper subset.

3 votes
1 answer
588 views

The character table of an abelian group

3 votes
2 answers
211 views

Michael Line is not Lindelöf

3 votes
2 answers
434 views

Let $G$ be a $p$-group and let $H$ be a proper subgroup of $G$. Show that $H$ is a proper subgroup of $N_G(H)$

3 votes
2 answers
149 views

$\omega_1$ is not Lindelof

3 votes
3 answers
361 views

Prove that the set of condensation points is closed

3 votes
1 answer
56 views

Showing that a set similar to Cantor set has complement with measure one

3 votes
0 answers
27 views

Subset of $X$ closed under countable disjoint unions and complements a $\sigma$-algebra?

3 votes
1 answer
58 views

$K$ is the splitting field of degree $p$ polynomial $f(x)$. If $[K:F] =tp, t \in \mathbb{N}$, $f(x)$ is irreducible

2 votes
1 answer
94 views

How to integrate with respect to $\overline{z}$

2 votes
2 answers
74 views

Find the residues for singularities of $f(z) = \frac{\cos z}{z^2(z- \pi )^3}$

2 votes
1 answer
53 views

The primitive $n^{th}$ roots of unity form basis over $\mathbb{Q}$ for the cyclotomic field of $n^{th}$ roots of unity iff $n$ is square free

2 votes
3 answers
131 views

Proving the sentence $X \lor Y {\implies}Z$

2 votes
2 answers
109 views

$G$ is a finite, simple, nonabelian group. If $|G:H| = p$, then $|\{gHg^{-1}\}|=p$

2 votes
0 answers
48 views

Showing that $T$ is Hilbert-Schmidt operator

2 votes
0 answers
32 views

Analytic function with $f(1/n) \in \mathbb{R}$ implies $f$ is real valued for $-1<x<1$ [duplicate]

2 votes
2 answers
45 views

Find the power series in powers of $x$ for the function

2 votes
3 answers
51 views

If $p$ is a prime and $a,b,c \in \mathbb{N}$, then does $p^a-p^b =p^c$? [duplicate]

2 votes
1 answer
62 views

Is $[\star]$ a limit point of the sequence $\langle [\frac{1}{1}] , [\frac{1}{2}], [\frac{1}{3}], \dots \rangle$?

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