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zibadawa timmy's user avatar
zibadawa timmy's user avatar
zibadawa timmy's user avatar
zibadawa timmy
  • Member for 10 years, 9 months
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42 votes

Why did no student correctly find a pair of $2\times 2$ matrices with the same determinant and trace that are not similar?

15 votes

Physical or geometric meaning of complex derivative

14 votes
Accepted

Is a group isomorphic to the internal product of its Sylow p-subgroups?

14 votes
Accepted

Difference between centralizer and center groups?

12 votes

Proof that $a+\frac{1}{a}\in\mathbb{Z}$ iff $a=\pm1$

9 votes

Is this matrix diagonalizable? Wolfram Alpha seems to contradict itself...

9 votes

Show that the function $f:X\to \mathbb R$ defined by $f(x)=d(x,A)$ is continuous.

8 votes

If $x$ is an element of $y$ and $y$ is an element of $z$, is $x$ an element of $z$?

8 votes
Accepted

How to prove that a group of order $72=2^3\cdot 3^2$ is solvable?

7 votes

If $A^2+A=0$,then $\lambda=1$ cannot be an eigenvalue of A.

7 votes
Accepted

Evaluate of $\lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n}$

7 votes

Riddles that can be solved by meta-assumptions

6 votes

Is $\sin z/z$ analytic at the origin?

6 votes

Confused with a statement

6 votes
Accepted

Why is the concept of a codomain useful?

5 votes
Accepted

Let $\varphi $:$G\to H$ be an onto group homomorphism. Show that if $K \unlhd G$, then $\varphi(K)\unlhd H$.

5 votes

In Cantor's Diagonalization Argument, why are you allowed to assume you have a bijection from naturals to rationals but not from naturals to reals?

5 votes
Accepted

$G \cong G \times H$ does not imply $H$ is trivial.

5 votes
Accepted

One-dimensional representations of S5

5 votes

$|G|=p^n$, $Z(G)=\langle w\rangle$, $Z(G)\subseteq$ a maximal subgroup; then $\exists f\in \operatorname{Aut}(G)\ , k\ne1\pmod p$ s.t. $ f(w)=w^k$?

5 votes

If $\int_E f=\int_E g$ then $f=g$ a.e.?

4 votes
Accepted

Generating Prüfer 2-group without its Frattini Subgroup

4 votes

Non-abelian groups that are "closest" to being abelian

4 votes
Accepted

How to generate the icosahedral groups $I$ and $I_h$?

4 votes
Accepted

A finite commutative ring with 1 whose elements satisfy a particular equation

4 votes

Elements of $\operatorname{Aut}(\operatorname{Aut}(G))$ acting as an identity on $\operatorname{Inn}(G)$

3 votes
Accepted

holomorphic function over the disk that is real on a closed curve must be constant

3 votes

Generalizing central automorphism group condition to endomorphisms

3 votes
Accepted

Semicircle contour for integrating $t^2/(t^2+a^2)^3$

3 votes

Question asks for what I can say about the topologies of $T$ and $T'$ where $T'$ is strictly finer than $T$

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