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Pp..'s user avatar
Pp..
  • Member for 9 years, 5 months
  • Last seen more than 9 years ago
21 votes
Accepted

$\liminf$ of a sequence of functions

14 votes
Accepted

Existence of a non-constant entire function

13 votes

Prove that an infinite sigma algebra contains an infinite sequence of disjoint sets and is uncountable

12 votes
Accepted

Problems with the proof that $\ell^p$ is complete

12 votes
Accepted

Why is Hawaiian earring not semilocally simply connected?

11 votes

Issue with Spivak's Solution

10 votes
Accepted

Summing up series which is similar to Taylor expansion

9 votes
Accepted

Convergence of a sequence of functions and their inverses

8 votes
Accepted

Function holomorphic except for real line and continuous everywhere is entire

8 votes
Accepted

If $\log_{12}54=a$ then $ \log_{6}12=?$

8 votes
Accepted

Solve for $n$, with factorial.

7 votes
Accepted

Show that $Y^2 + X^2(X+1)^2$ is irreducible over $\mathbf R$

7 votes
Accepted

How to prove, that solution of system $Ax = b$ exists only if there is no solution of $A^T y = 0$ and $b^T y = 1$?

7 votes
Accepted

Simplify the sum $ \sum_{k=1}^{\infty} (\frac{1}{2})^kk $

6 votes
Accepted

Embedding $L^2[0,1]$ into any Hilbert space?

6 votes
Accepted

Let A be a measurable set in R. Let B be all of it's densed points. is B necessarily open?

6 votes
Accepted

Prove that the set $X+Y$ is closed

6 votes
Accepted

How prove this matrix $A$ similar with $A^T$

6 votes
Accepted

Every affine variety in $\mathbb A^n$ consisting of finitely many points can be written as the zero locus of $n$ polynomials

6 votes
Accepted

Convergence in inner product space

5 votes

$E$ measurable set and $m(E\cap I)\le \frac{1}{2}m(I)$ for any open interval, prove $m(E) =0$

5 votes
Accepted

Prove that there is an infinite simple path in a Graph

5 votes
Accepted

Dense subset in sequence space

5 votes

How do I find the error of nth iteration in Newton's Raphson's method without knowing the exact root

5 votes
Accepted

Inner Product on $\mathbb{R}$ and on $\mathbb{C}$

5 votes

$\mathbb{R}$ with the lower limit topology is not second-countable

4 votes
Accepted

Linear operator norm

4 votes
Accepted

Solve the following equation for x and y:

4 votes
Accepted

Solve the Differential Equation $\frac{dy}{dx}=2+\sqrt{y-2x+3}$

4 votes
Accepted

Problem From Golan's Linear Algebra Book-Linear Transformation

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