Recent questions in Others

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0 answers
1301
Let $f:[0,1]\rightarrow{\mathbb{R}}$ be a monotone increasing (not necessarily continuous) function such that $f(0)>0$ and $f(1)<1$. Then there exists $x\in[0,1]$ such th...
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0 answers
1302
The set$$\{(x,y)\in \mathbb{N}\times\mathbb{N}| x^y \text{ divides } y^x,\:x\neq y,\:xy\neq0,\:x\neq1\}$$is finite.
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1303
Suppose a line segment of a fixed length $L$ is given. It is possible to construct a triangle of perimeter $L$, whose angles are $105^{\circ},\: 45^{\circ} \text{ and } 3...
1 votes
0 answers
1304
The real vector space $M_n(\mathbb{R})$ cannot be spanned by nilpotent matrices, for any positive integer $n$.
0 votes
0 answers
1305
Let $S \subseteq M_n(\mathbb{R})$ be a nonempty finite set closed under matrix multiplication. Then there exists $A\in S$ such that the trace of $A$ is an integer.
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1306
Given a linear transformation $T:\mathbb{Q}^4\rightarrow\mathbb{Q}^4$, there exists a nonzero proper subspace $V$ of $\mathbb{Q}^4$ such that $T(V)\underline\subset V.$
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1307
If G is a finite group such that the group $\text{Aut}(G)$ of automorphisms of $G$ is cyclic, then $G$ is abelian.
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0 answers
1308
There exists a countable group having uncountably many subgroups.
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1309
There exists a nonzero ideal $I \subseteq \mathbb{Z}[i]$ such that the quotient ring $\mathbb{Z}[i]/I$ is infinite $($here $i$ is a square root of $-1$ in $\mathbb{C})$.
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1310
There exists an injective ring homomorphism from the ring $\mathbb{Q}[x,y]/(x^2-y^2)$ into the ring $\mathbb{Q}[x,y]/(x-y^2)$.
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1311
The set $$\{n\in\mathbb{N} | n \text{ divides } a^3-1, \text{ for all integers } \text{$a$ such that gcd}(a,n)=1\}$$is infinite.
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0 answers
1312
The set of polynomials in the ring $\mathbb{Z}[x]$, the sum of whose coefficients is zero, forms an ideal of the ring $\mathbb{Z}[x]$.
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0 answers
1313
0 votes
1 answer
1315
all test is paid or not
4 votes
6 answers
1318