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4

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Unsure about how to prove this

abstract-algebra proof-writing

asked 3 mins ago brucemcmc 1

-1

votes

1

answer

13

views

existence of matrix

linear-algebra

answered 3 mins ago Nico 190

0

votes

0

answers

3

views

Euclidean distance in high dimensional spaces

euclidean-geometry

asked 4 mins ago HOANG GIANG 17

0

votes

0

answers

3

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Fundamental group as a product of normal subgroups

algebraic-topology homotopy-theory retraction

asked 4 mins ago PerelMan 585

0

votes

0

answers

6

views

Show $\hat{f} = \hat{F}$ implies $f = F$ in $L^2$

real-analysis fourier-analysis

asked 5 mins ago Alvis Nordkovich 104

0

votes

0

answers

27

views

Proof based on orthogonal matrix

matrices multivariable-calculus proof-explanation determinant orthogonal-matrices

modified 5 mins ago lydias 89

24

votes

0

answers

377

views

+50

How many nodes in the smallest $k$-dense graph?

combinatorics graph-theory directed-graphs

modified 6 mins ago Joseph Martin 412

0

votes

0

answers

3

views

The proof of the homotopy extension and lifting property (HELP)

general-topology algebraic-topology homotopy-theory

asked 6 mins ago Aolong Li 868

2

votes

2

answers

15

views

associative law for convolution of distribution with test functions

convolution

answered 7 mins ago Greg Grunberg 101

0

votes

0

answers

5

views

How did they make this mathematical jump in steps, in finding a determinant of a simple 3x3 matrix?

linear-algebra determinant

asked 7 mins ago iammax 190

1

vote

1

answer

35

views

Limit of some integrals.

integration analysis convergence

modified 7 mins ago gt6989b 34.2k

1

vote

0

answers

34

views

Interchanging Integration Order involving Fourier Transform

integration fourier-transform distribution-theory harmonic-analysis

modified 9 mins ago Hans 5,009

0

votes

0

answers

8

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Boolean expression simplification - Short problem

logic propositional-calculus boolean-algebra

asked 9 mins ago JohnJohnyPapaJohn 1

2

votes

1

answer

44

views

Prove that $P(A ∩ B) ≤ P(A ∪ B) ≤ P(A) + P(B)$

probability elementary-set-theory

modified 14 mins ago Heptapod 636

0

votes

0

answers

6

views

How ot use indicator variables as an objective function

linear-programming binary-programming

asked 15 mins ago user2567806 11

4

votes

0

answers

16

views

Interesting olympiad exponential equation and derived equations

trigonometry exponential-function contest-math

modified 17 mins ago Robert Howard 2,010

0

votes

1

answer

23

views

How can I sketch the graph of these rational functions?

algebra-precalculus

modified 18 mins ago John Wayland Bales 14.3k

1

vote

1

answer

26

views

Is this enough to prove linear independence?

linear-algebra proof-explanation

modified 20 mins ago Jair Taylor 8,829

0

votes

0

answers

3

views

Perturbation bound on approximate linear system

linear-algebra numerical-methods numerical-linear-algebra singularvalues

asked 20 mins ago Drew Brady 719

1

vote

0

answers

4

views

Natural Deduction Logic

proof-verification natural-deduction

asked 21 mins ago RachelR 6

1

vote

2

answers

17

views

Product ring isomorphism from example 11.6.3 in Artin's Algebra

abstract-algebra ring-theory commutative-algebra finite-fields ring-isomorphism

modified 21 mins ago Servaes 25.6k

2

votes

1

answer

29

views

Linear Programming - Labor Allocation

optimization linear-programming operations-research

answered 25 mins ago prubin 1,445

0

votes

0

answers

7

views

Routines for diagonalization of banded hermitian matrices?

eigenvalues-eigenvectors diagonalization

modified 25 mins ago Bernard 121k

0

votes

0

answers

16

views

Fibonacci spiral on sphere surface

calculus geometry spherical-coordinates

modified 26 mins ago Bernard 121k

0

votes

0

answers

6

views

Variance of Product of Ind. Variables

probability proof-verification

modified 26 mins ago YuiTo Cheng 1,693

2

votes

1

answer

14

views

If $f:X\to Y$ is bijective, then $(f^{-1})^{(-1)}(A)=f(A)$

elementary-set-theory inverse

answered 26 mins ago Kenny Wong 18.8k

0

votes

0

answers

16

views

Functions restricted to $\operatorname{Spec}(k[x,y]/(x^2,xy))$ with $k$ algebraically closed.

abstract-algebra algebraic-geometry

modified 27 mins ago Bernard 121k

1

vote

1

answer

12

views

Cumulative distribution function and Brownian motion

probability stochastic-calculus brownian-motion

modified 28 mins ago Kavi Rama Murthy 60.9k

0

votes

0

answers

5

views

HELP with SAS DATA programs

statistics computer-science programming

asked 28 mins ago DataD96 19

1

vote

0

answers

20

views

Any set of $\mathbb R$ is open iff it is the union of disjoint open intervals

general-topology

asked 28 mins ago Ray Romero 9

1

vote

0

answers

4

views

Radial term of the Laplacian in polar coordinates

polar-coordinates laplacian

modified 31 mins ago Robert Howard 2,010

0

votes

0

answers

22

views

What formulas of differential geometry am I missing?

multivariable-calculus derivatives differential-geometry reference-request laplacian

modified 31 mins ago Travis 60.4k

3

votes

1

answer

36

views

Constructing a graph with radius two.

combinatorics discrete-mathematics graph-theory geometric-construction planar-graph

modified 35 mins ago Servaes 25.6k

0

votes

0

answers

9

views

Finding the probablity density of a point for a multivariate gaussian distribution

covariance

modified 36 mins ago Kavi Rama Murthy 60.9k

5

votes

1

answer

31

views

How do I isolate $k$ in the following equation?

algebra-precalculus logarithms exponentiation

modified 36 mins ago Servaes 25.6k

0

votes

0

answers

7

views

CLT fro stochastic process.

probability-theory stochastic-processes

modified 39 mins ago openspace 3,394

0

votes

0

answers

5

views

probability of a non-central xhi-squared RV to be smaller than a chi-squared RV

probability

asked 43 mins ago dagcilibili 32

0

votes

1

answer

15

views

Notation for “Defined as proportional to”

notation

answered 46 mins ago PackSciences 879

0

votes

0

answers

27

views

What is symmetry in physics in the mathematical sense, using (Lie) groups

group-theory reference-request mathematical-physics classical-mechanics symmetry

modified 46 mins ago J. W. Tanner 2,067

-1

votes

1

answer

11

views

regular language proof

automata regular-language

answered 53 mins ago Berci 60.9k

0

votes

0

answers

20

views

linear algebra proof on even/odd functions

linear-algebra proof-writing

asked 53 mins ago jsiss 1

0

votes

0

answers

6

views

Expected value of a function of multiple random variables

probability probability-theory

asked 53 mins ago FourierFlux 98

3

votes

2

answers

95

views

Construct a continuous function $f: (0, 1) \rightarrow \mathbb R$ but is not differentiable at any point of $\{\frac{1}{1+n}: n \in\mathbb N\}$

real-analysis continuity

modified 56 mins ago José Carlos Santos 162k

0

votes

0

answers

12

views

Central Limit Theorem- Lapunow, Linderberg

probability-theory weak-convergence central-limit-theorem probability-limit-theorems

modified 57 mins ago John1357 20

1

vote

0

answers

8

views

Characteristic classes for $P \rightarrow G \rightarrow G/P$

lie-groups homology-cohomology characteristic-classes principal-bundles

asked 58 mins ago Fredulon 6

1

vote

1

answer

28

views

Surface area of spherical section delineated by 2 perpendicular circular planes/central angles

area spherical-coordinates spherical-trigonometry

answered 58 mins ago KY Tang 359

6

votes

2

answers

54

views

Laplacian of $1/r$ in a tensor

mathematical-physics distribution-theory dirac-delta fluid-dynamics laplacian

modified 1 hour ago Qmechanic 5,072

0

votes

0

answers

12

views

Some questions about integral equations.

real-analysis functional-analysis

asked 1 hour ago Rubén Fernández Fuertes 38

5

votes

1

answer

767

views

Why use infimum in definition of Quantile function

probability-distributions

modified 1 hour ago Community♦ 1

5

votes

1

answer

44

views

Combinatorics and ID

combinatorics

modified 1 hour ago Oldboy 8,275

0

votes

0

answers

19

views

Proving $￢∃x (P(x)) → ∀x (￢P(x))$

proof-verification logic first-order-logic quantifiers

asked 1 hour ago user525966 2,065

1

vote

0

answers

51

views

Reduces to $0$ of $S$-polynomial.

polynomials commutative-algebra groebner-basis monomial-ideals

modified 1 hour ago user26857 39.3k

0

votes

1

answer

20

views

Monomial ideal which is not saturated.

commutative-algebra ideals monomial-ideals

modified 1 hour ago user26857 39.3k

1

vote

1

answer

27

views

Calculating the annulus of a sphere with a differential change in theta

geometry triangle spherical-coordinates spheres

answered 1 hour ago Aretino 23.7k

1

vote

1

answer

23

views

Holomorphic Morse functions

differential-geometry differential-topology complex-geometry several-complex-variables morse-theory

answered 1 hour ago safety stegosaurus 26

0

votes

0

answers

18

views

Matrix and powers

matrices prime-numbers

modified 1 hour ago KarlPeter 680

1

vote

0

answers

6

views

Finding the limit $\lim_{n \to \infty} P_0^n$ for a European Cash-or-Nothing call option with $P=K^2\cdot \mathbf{1}_{\{S_T < K\}}$

probability-theory stochastic-processes stochastic-calculus martingales finance

modified 1 hour ago Rebellos 14.8k

0

votes

0

answers

7

views

Maximization of coupled circulants sum wrt some constraints

summation

modified 1 hour ago Francesco Reid 1

1

vote

1

answer

12

views

Inner direct sum and nonlinear operators

functional-analysis operator-theory nonlinear-analysis

answered 1 hour ago Matt Samuel 38.5k

0

votes

0

answers

14

views

Does an empirical distribution converge to the underlying distribution?

probability-distributions reference-request weak-convergence

modified 1 hour ago induction601 1,186

0

votes

0

answers

14

views

Inverse Fourier transform of complex fourier transform

fourier-analysis inverse fourier-transform

modified 1 hour ago s.dokaj 43

1

vote

1

answer

18

views

Question about an inequality in probability

probability-theory stochastic-processes

answered 1 hour ago d.k.o. 9,583

1

vote

1

answer

33

views

Proof of property of Markov chain

markov-chains

modified 1 hour ago Zhanxiong 8,926

2

votes

0

answers

35

views

Does every prime ideal of a commutative Noetherian ring R contain a minimal prime of Ann(R)?

commutative-algebra

modified 1 hour ago user26857 39.3k

1

vote

0

answers

12

views

Proof that makes use of the differentiability of a function and of its convex conjugate

measure-theory proof-writing convex-analysis lebesgue-measure convex-geometry

modified 1 hour ago STF 61

1

vote

0

answers

9

views

Projection Formula for Projective Morphisms

algebraic-geometry schemes

asked 1 hour ago KarlPeter 680

2

votes

0

answers

19

views

Attempting to simplify a quadruple system

algebra-precalculus systems-of-equations nonlinear-system

modified 1 hour ago math guy 11

3

votes

2

answers

26

views

Evaluating $\int_{} \frac{xe^{2x}}{(1+2x)^2}dx$ via integration by parts

integration

modified 1 hour ago Mike R. 2,453

4

votes

0

answers

40

views

Canonical bundle of blow up at singular point

differential-geometry algebraic-geometry differential-forms complex-geometry blowup

modified 1 hour ago klirk 2,698

1

vote

0

answers

9

views

can a Markov chain have a periodic and transient state?

probability probability-theory markov-chains

modified 1 hour ago Bernard 121k

0

votes

1

answer

16

views

Is a hole at a vertical asymptote recognized?

rational-functions

answered 1 hour ago YiFan 4,025

0

votes

0

answers

9

views

Weak convergence of $(n^{-1}T_{k,n})_{n \geq \lceil k/2 \rceil}$

probability

asked 1 hour ago elvenpath98 6

0

votes

0

answers

11

views

Using Base Change Argument

commutative-algebra

asked 1 hour ago KarlPeter 680

1

vote

0

answers

22

views

Find the adjoint of a linear operator

linear-algebra matrices

modified 1 hour ago Pipluposha 8

0

votes

0

answers

13

views

Square root and similarity between integer matrices

matrix-equations matrix-analysis matrix-congruences

modified 2 hours ago darij grinberg 11.3k

0

votes

0

answers

6

views

Markov Chain generated by iterations of functions

probability statistics stochastic-processes markov-chains

asked 2 hours ago Natalie_94 24

3

votes

0

answers

37

views

Coloring the Natural Numbers

number-theory graph-theory

modified 2 hours ago jvdhooft 5,600

7

votes

0

answers

65

views

A single set of moves $S$ that, if repeated, solves the Rubik's cube from any state

group-theory proof-verification finite-groups alternative-proof rubiks-cube

modified 2 hours ago Wesley Strik 2,052

0

votes

0

answers

4

views

Computing matrix inverses with Lu factorizations and repeated left division.

linear-algebra matrices numerical-methods

asked 2 hours ago Temirzhan 492

0

votes

0

answers

9

views

Positive definiteness and eigenvalue ellipses

matrices inequality positive-definite

asked 2 hours ago mk37972 1

0

votes

0

answers

9

views

How to numerically solve a partial differential equation containing two time derivatives?

pde numerical-methods

modified 2 hours ago mrtaurho 5,465

-2

votes

3

answers

34

views

If $H\triangleleft G$ and $H\subset K \leq G$ then $H\triangleleft K$

abstract-algebra group-theory

modified 2 hours ago Chris Custer 13.6k

0

votes

2

answers

29

views

Limits and matrix determinants

matrices limits determinant

modified 2 hours ago Song 14.1k

1

vote

0

answers

10

views

Connections between Ext and vertex

representation-theory homological-algebra local-representation-theory

asked 2 hours ago RhythmInk 1,708

0

votes

0

answers

8

views

Compute all the irreducible representations of $\mathbb{Z}_{2}^{k}$

finite-groups representation-theory

asked 2 hours ago Ya G 469

0

votes

0

answers

13

views

Verify $(\chi_1\mid \chi_2)=0$, $(\chi_1\mid \chi_1)=1$, $(\chi_2\mid \chi_2)=1$

finite-groups representation-theory

asked 2 hours ago Ya G 469

1

vote

1

answer

23

views

Theorem 2.34 Baby Rudin (Compact subsets of metric spaces are closed): How is his proof general enough?

real-analysis metric-spaces proof-explanation compactness

answered 2 hours ago Eric Wofsey 187k

0

votes

1

answer

36

views

Simultaneous equations involving exponentials

exponential-function systems-of-equations

modified 2 hours ago Carlitocarlos 1

0

votes

1

answer

46

views

How many solutions are there to the linear equation?

combinatorics

modified 2 hours ago John Omielan 2,900

4

votes

2

answers

60

views

Ideal of $\mathbb{Z}[x]$ generated by $3$ and $x^2+1$ is proper

abstract-algebra ring-theory ideals

modified 3 hours ago user26857 39.3k

3

votes

0

answers

25

views

Is it true that $\lim_{n \to \infty} {(P(\forall i,j\leq n \text{ } [X_i, X_j] = e))}^{\frac{1}{n}} = P(X_1 \in Z(G))$?

probability abstract-algebra group-theory probability-theory independence

modified 3 hours ago user26857 39.3k

0

votes

0

answers

6

views

If $\kappa$ is a transition kernel and $f$ is measurable, is $\int f(\;\cdot\;,\omega_2)\kappa(\;\cdot\;,{\rm d}\omega_2)$ measurable?

probability-theory measure-theory

asked 3 hours ago 0xbadf00d 1,975

1

vote

4

answers

805

views

How to construct a circle tangent to another circle and a line?

euclidean-geometry circle geometric-construction tangent-line locus

modified 3 hours ago MarianD 454

2

votes

0

answers

15

views

How to show minimal surface equation is a non-uniform elliptic equation

pde elliptic-equations

modified 3 hours ago Daniele Tampieri 2,292

5

votes

0

answers

27

views

Extension group between Verma modules for $sl_2$

representation-theory lie-algebras verma-modules

modified 3 hours ago zzy 2,612

3

votes

0

answers

30

views

About a Corollary of Isaacs' “character theory of finite groups”: does the converse implication hold?

group-theory finite-groups representation-theory characters

modified 4 hours ago ciccio 67

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