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Interesting 13 Bountied Hot Week Month
3 votes
3 answers
811 views

Spanning set and Subset

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Bhaskar Vashishth
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0 answers
19 views

Intersection of A-excircle and circumcirlce

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Amelia Tearheart
  • 187
0 votes
0 answers
7 views

Using Banach-Tarski to disprove the existence of a volume function in $\mathbb{R}^3$

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Keertan
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1 vote
0 answers
35 views

Maximum Value of a Fractional Quadratic Form over the Complex Unit Sphere with Projection Constraint

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V.K.
  • 21
0 votes
1 answer
1k views

Inverse Laplace Transform With Dead Time

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13 votes
1 answer
707 views

Challenging identity regarding Bell polynomials

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DroneBetter
  • 846
10 votes
2 answers
1k views

Polylogarithms of negative integer order

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DroneBetter
  • 846
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0 answers
8 views

Is the dx really necessary for definite integrals?

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Munchrr
  • 424
0 votes
0 answers
11 views

The median of a frequency distribution and $g(x)=\sum_{k=1}^n f_k |x-x_k|$

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Dharmendra Singh
  • 1,385
0 votes
0 answers
13 views

Derivative of $e^{Qt}$ (when $Q$ is a matrix)?

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stats_noob
  • 4,283
2 votes
0 answers
54 views

Consistency of the notions of internal logic/language of a topos

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Westlifer
  • 836
5 votes
2 answers
205 views

Prove that $\mathbb{Q}(\alpha, \beta, \gamma, r_1) = \mathbb{Q}(r_1, r_2, r_3, r_4)$

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orangeskid
  • 57.6k
0 votes
3 answers
769 views

Finding Lagrangian of a system (Oscillations in a parabolic trough)

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Gonçalo
  • 16.7k
3 votes
1 answer
58 views

When/why is substitution valid for equations?

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heropup
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0 votes
1 answer
40 views

When is $\sum_{i = 0}^n (-1)^i\binom{A}{i}\binom{B}{n-i} \neq 0$?

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Thomas Andrews
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3 votes
1 answer
748 views

Changing a simplex grid to an orthogonal grid.

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7 votes
2 answers
290 views
+50

Graphing the rational function $f(x)=\frac{3x}{x^2+x-2}$

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Toby Bartels
  • 5,351
5 votes
3 answers
135 views

Remote generation of functions

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flippiefanus
  • 226
0 votes
1 answer
31 views

Is every nilpotent element of a ring, a clean element

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Maths is good
  • 855
3 votes
2 answers
323 views

Combinatorial proof of $\sum_{j= m}^n {j \brace m} (m+1)^{n-j} = {n+1\brace m+1}$

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RobPratt
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2 votes
1 answer
3k views

Complete Sufficient Statistic for double parameter exponential

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User1865345
  • 719
5 votes
1 answer
75 views

De Rham cohomology of Klein Bottle without Mayer - Vietoris sequence

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Martin Sleziak
  • 56.5k
1 vote
1 answer
37 views

start from the point $O$ and return to the point $O$ after $2n$ steps, as illustrated in the figure below.

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Thomas Andrews
  • 188k
2 votes
0 answers
21 views

Find the least $n$ such that $n^{n}$ does not divide $1_{2}\times12_{3}\times123_{4}\times\cdots\times(1:2:3:\cdots:2025)_{2026}$

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Thirdy Yabata
  • 1,114
0 votes
1 answer
57 views

How to check the integral inequality appearing in Boltz Problem

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Gonçalo
  • 16.7k
3 votes
3 answers
96 views

Prove $BE^2 = AE \cdot AB$ in an isosceles right triangle with a perpendicular condition

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JMP
  • 22.9k
2 votes
0 answers
22 views

Are there butcher tables for adaptive embedded runge kutta 12(10) methods that DON'T use the second order formulation?

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Danny
  • 121
1 vote
1 answer
757 views

Symmetric polynomial identities: $(x,y,z)^n$ in terms of $\sigma _1=x+y+z$, $\sigma _2 = xy+yz+xz$ and $\sigma _3 = xyz$

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6 votes
0 answers
113 views

On conditions for $\lvert R/(I+J)\rvert \ge \lvert I\cap J/IJ\rvert$

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Bhaskar Vashishth
  • 12.2k
4 votes
3 answers
289 views

Computing Galois group of $\mathbb Q(\sqrt2,\sqrt3,\sqrt{(9-5\sqrt3)(2-\sqrt2)})$

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Bhaskar Vashishth
  • 12.2k
16 votes
2 answers
3k views

Book recommendations for commutative algebra and algebraic number theory

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Bowei Tang
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3 votes
2 answers
894 views

Given 100 coin tosses, the largest string of same results in a row is...?

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lonza leggiera
  • 33k
0 votes
2 answers
406 views

Prove using lcm of a number to find there exists n consecutive numbers for which f is constant & finding the greatest number of elements of a set?

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RobPratt
  • 52.6k
1 vote
0 answers
41 views

The geometry of $ 2^2 = \left(y+\frac{1}{y}\right)^2 - \left(y-\frac{1}{y}\right)^2 $

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Folding Circles
  • 429
1 vote
0 answers
35 views

A cohomological proof that $\mathbb{R}$ has Property (T)--- what is wrong?

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Student
  • 73
1 vote
5 answers
123 views

Let $A$ and $B$ be two nonempty bounded subsets of $\mathbb{R}$. Prove $\sup B \leq \sup A$.

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Robert Shore
  • 26.5k
1 vote
1 answer
31 views

Inequality for central moments of bounded r.v. $\mu_3^2-2\mu_2^3\leq0$?

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Henry
  • 173k
1 vote
0 answers
43 views

Proving matrix inverse properties for $n\times n$ matrices using Einstein notation, Levi-Civita symbols, and the generalized kronecker delta issue.

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Gerald
  • 445
1 vote
0 answers
53 views

When does the inverse of a sequence of matrices converge entrywise?

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pie
  • 9,515
2 votes
1 answer
97 views

Chinese remainder theorem in rngs (rings without identity)

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Bhaskar Vashishth
  • 12.2k
0 votes
2 answers
764 views

Show that the recursion $f(n) = 2f(n-1) + f(n-2)$ for $n \ge 2$ and $f(0) = 1, f(1) = 3$ is true.

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  • 1
1 vote
2 answers
807 views

An Introduction to Theory of Groups by Joseph J. Rotman - Exercise 2.21 - (ii)

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Bhaskar Vashishth
  • 12.2k
4 votes
1 answer
40 views

Showing that under certain conditions every cogenerator is a generator.

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Bhaskar Vashishth
  • 12.2k
2 votes
2 answers
811 views

How to find the sign of the determinant?

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Bhaskar Vashishth
  • 12.2k
0 votes
2 answers
765 views

Determine whether, for any set A, it is true that $P(\bar{A})= P(U) - P(A)$

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Bhaskar Vashishth
  • 12.2k
4 votes
0 answers
134 views

Logic-Compactness in complete lattice

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Florian
  • 51
4 votes
1 answer
121 views

Algebras over a ring with division by scalars when possible

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Jakobian
  • 16.2k
4 votes
2 answers
70 views

If $L/K$ is purely inseparable and $M/K$ is arbitrary, then $|\mathrm{Spec}(L \otimes_K M)| = 1$

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Bhaskar Vashishth
  • 12.2k
1 vote
0 answers
21 views

Differential of the identity function between R with distinct differential structures

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IsAdisplayName
  • 2,069
0 votes
0 answers
77 views

Local extrema of an integral involving the floor function

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Gonçalo
  • 16.7k
2 votes
1 answer
124 views

When can a function be approximated by a series of polynomials where every time we add a term of higher degree?

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Lost in Nowhere
  • 300
1 vote
1 answer
182 views
+200

Two initially large shoulder-to-shoulder battalions shoot each other, how many are left standing?

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Evariste
  • 2,737
1 vote
1 answer
52 views

$f_n(x) := 1+\sin(n \pi x)$, $f_n^k$ converges weakly to a constant $c_k$.

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Daniel Smania
  • 9,258
2 votes
1 answer
75 views

Why does ergodicity for functions of one coordinate imply ergodicity for all $p$-tuples?

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The Other Terry
  • 2,039
11 votes
5 answers
243 views

Is there a simple geometric interpretation of the identity $a(1 - b^{2}) + b(1 - a^{2}) = (a + b)(1 - ab)$?

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Somos
  • 37.7k
-1 votes
0 answers
24 views

Domain and Range with Linear Inequalities in Desmos

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psutt14
  • 1
2 votes
1 answer
143 views

What is $k! \bmod n$ if $k = 10^i$ and $n = 10^{19} + 51$ (prime)

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DanielV
  • 24.7k
2 votes
2 answers
738 views

Test symmetricity for a sparse matrix

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  • 1
1 vote
1 answer
85 views

How to prove that the recurrence $x_{n+1} = \frac{\max(x_n,1)}{x_{n-1}}$has period 5?"

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jjagmath
  • 24.7k
0 votes
0 answers
22 views

Minimizing entropy of a poset heuristic

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Shini
  • 1
3 votes
1 answer
80 views

Determine the surface area of Archimedean solids with radius 1

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Intelligenti pauca
  • 57k
3 votes
3 answers
139 views

Does this $2$-dimensional difference equation have a closed-form solution?

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Bhaskar Vashishth
  • 12.2k
5 votes
2 answers
638 views

conjecture about convergence of a sequence of inverse matrices.

pie's user avatar
pie
  • 9,515
4 votes
1 answer
750 views

Software for symbolic matrix operations

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CommunityBot
  • 1
0 votes
0 answers
11 views

Inverse of Dirichlet autoconvolution

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24th_moonshine
  • 711
0 votes
0 answers
16 views

Is the set of PMV clones on {0,1} countable, or of size continuum?

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user107952
  • 24.9k
0 votes
0 answers
36 views

Prove PF⋅PG=PB⋅PD on tangents to a conic with two externally bitangent circles

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hbghlyj
  • 6,493
3 votes
1 answer
29 views

Expectation of stopped sum of iid standard normals

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optimal control
  • 735
5 votes
1 answer
251 views

Solving an infinite differential equation

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Rócherz
  • 4,281
0 votes
1 answer
906 views

Find continued fractions and corresponding rationals

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  • 1
3 votes
0 answers
52 views

Is it possible to construct a category with finite products which provably does not have any choice of cartesian monoidal structure?

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Nazar Androshchuk
  • 41
2 votes
0 answers
34 views

Limits in functor categories are pointwise, using representability

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sdcvvc
  • 10.9k
1 vote
0 answers
42 views

Eigenvalues-eigenvectors in a system of differential equations

swang's user avatar
swang
  • 23
8 votes
1 answer
71 views

Truncated functions converging to zero weakly imply that the function is zero?

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Bruno B
  • 8,375
8 votes
0 answers
233 views

Does Birkhoff-von Neumann's Theorem easily imply Hall's Marriage Theorem or equivalent?

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Alma Arjuna
  • 7,418
3 votes
1 answer
898 views

On what interval does it converge absolutely, uniformly,fail to converge uniformly?

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CommunityBot
  • 1
2 votes
0 answers
106 views

Is it ever useful to consider cofibrations which satisfy the HEP only with respect to a proper subclass of spaces?

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FD_bfa
  • 4,927
0 votes
0 answers
49 views

What is the area of the set of points with escape count n in a generic Burning Ship fractal?

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Daniel Smania
  • 9,258
9 votes
0 answers
149 views

CW Structure on Self-Homeomorphism Groups

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FD_bfa
  • 4,927
2 votes
1 answer
187 views

Prove the envelope of lines is a hyperbola

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hbghlyj
  • 6,493
1 vote
0 answers
189 views

What known formulas are there that yield sequences with no known non-trivial cycles?

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Simon Goater
  • 931
2 votes
2 answers
34 views

Does a system of "Cyclic Conjugate Priors" exist?

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Henry
  • 173k
2 votes
0 answers
22 views

Why two real smooth conics cannot be tangent at non-real finite points, in contrast with cubic–circle examples

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hbghlyj
  • 6,493
0 votes
0 answers
31 views

Completion of a sigma-field

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spaceisdarkgreen
  • 70k
0 votes
1 answer
79 views

For any square matrix $A \in M_{n \times n}(\mathbb{R}), \ker(A) \subseteq \ker(A^2)$

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Lost in Nowhere
  • 300
0 votes
0 answers
9 views

Neumann (no-flux) boundary conditions for nonlinear coupled PDEs

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andrix
  • 155
2 votes
3 answers
6k views

Simple way for solving generic work and time problems

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true blue anil
  • 49.9k
3 votes
2 answers
407 views

For $a,b,c,d\in \Bbb N$ prove that $(a-b)(c-a)(d-a)(c-b)(d-b)(d-c)$ is divisible by $12$

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Bill Dubuque
  • 285k
3 votes
1 answer
57 views

A gentle Course in Local Class Field Theory, Proof of Corollary 12.6

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Plantation
  • 4,186
1 vote
0 answers
289 views

Proof that Sanov subgroup is free of rank 2

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mezzoctane
  • 1,969
0 votes
0 answers
25 views

Orthonormal basis of $\mathcal{P}_n$ (polynomials of order $n$) on $X\in \mathbb{R}^2$ (step 2 of Vioreanu-Rokhlin quadrature)

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some_user
  • 191
0 votes
1 answer
745 views

Example of 1D and 2D Poisson Equation

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6 votes
2 answers
5k views

Example of a non-linear isometry?

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Hans Lundmark
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1 vote
1 answer
1k views

What are the relations between geometric multiplicity and algebraic multiplicity, concerning diagonalizability?

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9 votes
6 answers
5k views

On the GCD of a Pair of Fermat Numbers

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Bill Dubuque
  • 285k
0 votes
0 answers
35 views

Prove $f:\mathbb{Q_{+}}\times\mathbb{Q}\ni (x,y)\mapsto x^y\in\mathbb{R}$ is uniformly continuous on bounded sets.

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tchappy ha
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