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notaMathqueen
  • Member for 1 year, 4 months
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4 votes
1 answer
115 views

Proof $f:\frac{(\ln(\frac{\pi}{2x}))^\gamma}{(\cos x)^\beta (\sin x)^\alpha}$ is Lebesgue integrable.

3 votes
1 answer
102 views

Composition of uniform function and continuous function

2 votes
1 answer
79 views

Air fan problem - fluid dynamic

2 votes
1 answer
63 views

Proof that in $\mathbb{R}^+$ the function $\frac{1}{1+x}$ is continuous

2 votes
1 answer
39 views

convergences of a row of functions according to a different metric

2 votes
2 answers
43 views

Hausdorff metric:When A is closed, $[A]_r$ is closed for every $r \in\mathbb{R}^+$.

2 votes
3 answers
61 views

$V$ with $ A \subseteq V $ and $V_0 = \bigcap_{V \in \mathcal{V}}V$. If $V_0$ is open than $A$ is open.

2 votes
1 answer
90 views

What is the limit of $\int_{\mathbb{R}}f(x)|\sin( \lambda x)| dx$ for all integrable functions $f:\mathbb{R} \rightarrow \mathbb{C}$?

1 vote
1 answer
79 views

Does there exist an unique continuous bounded $f$ such that $f(x)= \frac{\sin(f(x))}{2+x^2} - \frac{\cos^2(x)}{1+e^x}$?

1 vote
1 answer
61 views

Is $F:\mathbb{R} \rightarrow \mathbb{R}: x \mapsto \int_0^\infty \frac{\arctan(xt)}{1+t^2}dt$ differentiable in $x\not= 0$?

1 vote
1 answer
40 views

For which values of $p \in \mathbb{R} $ is the integral $I = \int_{0}^{\infty} \frac{x^p}{x^2+a^2}dx$ convergent?

1 vote
1 answer
37 views

Prove that the family $\{f_n\}$ is normal in $\mathbb{D}\backslash \{0\}$ if and only if f has a removable singularity at $z = 0$.

1 vote
1 answer
27 views

Intersection of open sets and subsets

1 vote
0 answers
63 views

Counterexample that for pointwise limit $lim_{n \rightarrow \infty} f_n(x_n) = f(a)$

0 votes
1 answer
64 views

Is $ f: \mathbb{C} \rightarrow \mathbb{C} : z \rightarrow z|z| $ complex differentiable?

0 votes
0 answers
22 views

Is $\mathbb{R}^p \backslash \{0\}$ separable for $2\leq p$

0 votes
1 answer
49 views

Calculating limits with theorem of Lagrange

0 votes
1 answer
46 views

Are the non-empty finite bounded subsets of $\mathbb{R}^2$ complete with respect to the Hausdorff metric?

0 votes
1 answer
40 views

What do we know about the set AB if A en B non-empty subsets of $\mathbb{R}_0^+$ with different conditions on A and B

0 votes
2 answers
58 views

Is $\lim_{x \rightarrow 1} \sum_{n=1}^\infty \frac{nx^2}{n^3+x}=\sum_{n=1}^\infty \frac{n}{n^3 +1}$ correct?

0 votes
0 answers
49 views

proof of total differentiable $f(x,y)=\frac{xy}{(x^2+y^2)^\alpha}$

0 votes
2 answers
27 views

Does $g: \mathbb{R^3} \rightarrow \mathbb{R}: (x,y,z) \rightarrow \frac{f}{1+x^2+y^2+z^2}$ reaches its max/min value

0 votes
1 answer
50 views

Functions between complete metric space and metric space

0 votes
0 answers
50 views

$\Omega_1$ and $\Omega_2$ open and connected in complex plane $\Omega_1 \cap \Omega_2 \neq \emptyset$, $\Omega_1 \cup \Omega_2$ also connected.

0 votes
2 answers
48 views

Holomorphic function: proving that $0 \leq f'(x)$ under conditions

0 votes
1 answer
49 views

Calculate $\int_{\gamma} \frac{1}{(z-1-i)^2} dz$ were $\gamma$ is a smooth curve from 2i to 2

-4 votes
1 answer
74 views

A function in $\Bbb{Q}$ that is not bounded but is bounded in $\Bbb{R}$ [closed]