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3

votes

3

answers

49

views

Distance between two lines (planes).

linear-algebra vectors analytic-geometry 3d

answered 2 mins ago Quanto 39.8k

4

votes

4

answers

94

views

equation with quadratic power

algebra-precalculus

modified 3 mins ago Glorfindel 3,582

0

votes

1

answer

25

views

what is the problem with this method while integrating $(e^x-(2x+3)^4)^3$?

calculus integration ordinary-differential-equations derivatives indefinite-integrals

modified 3 mins ago halrankard 2,148

0

votes

0

answers

20

views

Find all functions $f$ that satisfy the following

complex-analysis connectedness analytic-functions

modified 4 mins ago md2perpe 14k

1

vote

4

answers

17

views

Rolling Dice Game, Probability of Ending on an Even Roll

probability-theory dice

answered just now JMoravitz 62.4k

0

votes

1

answer

12

views

Inequality $E(xy)<E||xy||$

inequality expected-value

answered 5 mins ago richard gayle 409

1

vote

1

answer

42

views

How do I solve $(py - qy^{n}) + y' = 0$ using an integrating factor?

ordinary-differential-equations

modified 7 mins ago Josh B. 1,904

-1

votes

0

answers

20

views

Consider the convergent alternating series $\Sigma^{\infty}_{n=1} (-1)^n\frac{1}{(n+4)^2}$.

calculus approximation

modified 7 mins ago HaKuNa MaTaTa 4,615

0

votes

0

answers

9

views

How do I find (LCM^k )modulo m?

number-theory exponentiation gcd-and-lcm

asked 8 mins ago Bhavesh Wadhwani 1

6

votes

0

answers

46

views

An illusionist and his assistant are about to perform the following magic trick.

combinatorics contest-math

modified 9 mins ago alpmu 35

3

votes

1

answer

37

views

Example of absolutely continuous function $f$ with $\sqrt{f}$ not absolutely continuous

real-analysis measure-theory continuity

answered 10 mins ago Greg Martin 48k

4

votes

2

answers

1k

views

List all subgroups of $\mathbb Z_6$ and $\mathbb Z_8$

group-theory cyclic-groups

modified 11 mins ago Community♦ 1

0

votes

0

answers

16

views

Why does the ordering function invert itself?

permutations

modified 12 mins ago eric_kernfeld 121

0

votes

0

answers

10

views

The finite-dimensional distributions for a Wiener process are given by this formula?

probability-distributions reference-request stochastic-processes brownian-motion wiener-measure

asked 13 mins ago Andrew Shedlock 900

0

votes

1

answer

17

views

$(A^c\times B)\cup(A\times B^c)\cup(A^c \times B^c)=(A^c\times Y)\cup(X\times B^c)$

general-topology

answered 16 mins ago Brian M. Scott 509k

0

votes

0

answers

2

views

Visualise Gram sets of nonnegative polynomials in the cone of PSD matrices

polynomials visualization positive-semidefinite toeplitz-matrices hermitian-matrices

asked 16 mins ago Viktor Glombik 3,683

94

votes

0

answers

3k

views

Convergence of $\sum_{n=1}^{\infty} \frac{\sin(n!)}{n}$

real-analysis sequences-and-series convergence-divergence

modified 16 mins ago ShpielMeister 111

1

vote

0

answers

6

views

Add smaller Hamiltonian circuits to make bigger one

hamiltonian-path

asked 17 mins ago Swebert Correa 11

1

vote

1

answer

14

views

construct matrix group in GAP

group-theory gap

answered 19 mins ago Derek Holt 64.5k

0

votes

1

answer

11

views

'Classical' Infinitesimals and Tangent Spaces

differential-geometry infinitesimals tangent-bundle tangent-spaces quasiconformal-maps

answered 20 mins ago Basel J. 744

0

votes

0

answers

31

views

Prove that $f(x) \leq K \cdot\exp(L\cdot \int_a^x g(t)dt)$

real-analysis calculus analysis inequality

modified 20 mins ago enzotib 6,718

0

votes

1

answer

27

views

Is $T$ considered a constant after the integration?

integration physics distribution-theory

answered 20 mins ago md2perpe 14k

0

votes

3

answers

29

views

Do the trajectories found in primed and unprimed are the same?

ordinary-differential-equations classical-mechanics

answered 25 mins ago Cesareo 17.3k

5

votes

2

answers

91

views

+100

Fourier-like family total in $L^2(-\pi,\pi)$

linear-algebra functional-analysis fourier-analysis hilbert-spaces

modified 26 mins ago Bananach 5,754

2

votes

1

answer

20

views

Preservation of convergence in measure by absolutely continuous measures

probability-theory measure-theory convergence-divergence

modified 28 mins ago StubbornAtom 11.6k

1

vote

1

answer

24

views

Number of non-decreasing functions on rectangles

combinatorics order-theory

modified 31 mins ago Phicar 6,884

3

votes

1

answer

83

views

How do I understand this direct limit?

algebraic-geometry commutative-algebra category-theory

modified 32 mins ago Stahl 18.9k

0

votes

1

answer

27

views

Dirac Delta function in the form of rectangular function

functions signal-processing dirac-delta

answered 33 mins ago md2perpe 14k

0

votes

0

answers

6

views

Formula for the multivariate cumulative distribution function (continuous case)

probability probability-theory probability-distributions cumulative-distribution-functions

modified 33 mins ago STF 1,831

0

votes

0

answers

69

views

Why are the supremums of this linearly interpolated function equal?

real-analysis general-topology proof-explanation

modified 35 mins ago Ricky_Nelson 845

1

vote

1

answer

17

views

Example which proves that a closed subset of an incomplete metric space need not be complete.

metric-spaces

answered 37 mins ago KCd 20.4k

2

votes

3

answers

37

views

What is the relationship between the Leibniz integral rule and the dominated convergence theorem?

calculus integration probability-theory proof-explanation expected-value

answered 37 mins ago Foobaz John 28.4k

1

vote

0

answers

13

views

A problem of prime elements on a number field $L$

number-theory algebraic-number-theory

modified 38 mins ago Jose Camarillo 589

0

votes

0

answers

19

views

Efficient Method to Find A Root and/or Minima of A Multivariate Polynomial

multivariable-calculus polynomials algorithms roots maxima-minima

modified 41 mins ago DUO 1

1

vote

0

answers

19

views

Is a field extension of the form $\mathbb C[X, Y]/\mathfrak m$ isomorphic to $\mathbb C(k)$ for some algebraic $k$?

commutative-algebra field-theory extension-field

asked 43 mins ago Siddharth Bhat 5,774

0

votes

1

answer

15

views

Why $(b \rightharpoonup c ) = b\cdot c$ when $b,c \in A$?

abstract-algebra hopf-algebras associativity

answered 45 mins ago Andreas Blass 57.8k

3

votes

3

answers

78

views

Compute $\iint (x+y)\,dx\, dy$ with circle constraint $x^{2}+y^{2}=x+y$

integration multivariable-calculus polar-coordinates multiple-integral

modified 48 mins ago Tom Sharpe 465

1

vote

3

answers

485

views

How to visualize Reverse Triangle Inequality $||\mathbf{a}| − |\mathbf{b}|| ≤ |\mathbf{a} − \mathbf{b}|$?

complex-analysis inequality intuition visualization

modified 48 mins ago Analysis JD 997

0

votes

0

answers

22

views

Fast Numerical Approximation to system of non-linear equations

numerical-methods systems-of-equations nonlinear-system

modified 51 mins ago An Nguyen 11

0

votes

0

answers

11

views

An upper-bound for variance of a random variable satisfying a linear inequality

probability probability-theory probability-distributions expected-value variance

asked 52 mins ago Math_Y 231

0

votes

0

answers

14

views

Book for self-teaching invariant measures

reference-request dynamical-systems book-recommendation chaos-theory non-linear-dynamics

modified 53 mins ago J. W. Tanner 41.6k

0

votes

1

answer

15

views

Uniform convergence of $\sum_{k=0}^{\infty}(-1)^k\frac{[\ln(1+x^2)]^k}{k!}$ on $\mathbb{R}$.

calculus sequences-and-series

modified 55 mins ago RRL 68.2k

2

votes

2

answers

20

views

congruent matrices

linear-algebra matrices modular-arithmetic transpose

modified 56 mins ago Will Jagy 119k

0

votes

1

answer

29

views

The locus of vertex of a parabola, given that an orthogonal intersection is made with another having specified latus rectum and orientation.

conic-sections

modified 58 mins ago Aretino 33.1k

2

votes

0

answers

33

views

+100

Toeplitz Kernel Question

complex-analysis operator-theory invariant-subspace hardy-spaces winding-number

modified 1 hour ago Daniele Tampieri 5,052

2

votes

0

answers

62

views

Turning on a nuclear briefcase with the smallest possible number of keystrokes

combinatorics logic puzzle extremal-combinatorics

modified 1 hour ago Batominovski 46.2k

0

votes

1

answer

7

views

Matrix algebra in least squares regression

matrices linear-regression

answered 1 hour ago PePeLoTe alias TaChIdOk 13

1

vote

0

answers

17

views

Closed Curve Through an Event in Spacetime

differential-geometry differential-topology general-relativity

asked 1 hour ago Bryant 31

1

vote

1

answer

26

views

Intersecting diameter and chord

geometry euclidean-geometry systems-of-equations triangles circles

modified 1 hour ago Michael Rozenberg 159k

2

votes

1

answer

24

views

Showing that a set of integers $A=\Bbb N^*$ where $A$ has two properties

induction

modified 1 hour ago A.Sharma 1,892

-1

votes

0

answers

25

views

Word or phrase for $|v|^2$

terminology norm

asked 1 hour ago Jason S 2,733

2

votes

0

answers

33

views

What information is contained in the 'list of cells' of CW-complexes

algebraic-topology riemannian-geometry cw-complexes morse-theory

modified 1 hour ago Jan Bohr 4,523

0

votes

1

answer

27

views

Given N independent random variables, when does independence stops holding?

probability measure-theory independence

answered 1 hour ago Robert Israel 383k

2

votes

0

answers

32

views

How do the Christoffel symbols on an abstract manifold relate to those on submanifolds?

differential-geometry connections submanifold

modified 1 hour ago Maximilian Janisch 9,158

0

votes

0

answers

28

views

orientable manifold with $k$-connected component.

differential-geometry differential-topology geometric-topology orientation

modified 1 hour ago adawi 1

0

votes

0

answers

17

views

Best way to understand behavior of a deterministic dynamical system?

dynamical-systems

modified 1 hour ago Sam 645

2

votes

0

answers

16

views

representing of expectation for submatrices

probability matrices expected-value random-graphs random-matrices

modified 1 hour ago user4164 283

0

votes

4

answers

71

views

Locus of a complex number $z$ when locus of $z^2$ is known

complex-numbers locus

modified 1 hour ago mjw 3,101

8

votes

1

answer

109

views

Residue Theorem Integral

complex-analysis residue-calculus

modified 1 hour ago metamorphy 16.9k

1

vote

0

answers

24

views

Examples list of Theorems which need continuity property as a necessary condition

examples-counterexamples fixed-point-theorems fixed-points

asked 1 hour ago zeraoulia rafik 6,111

0

votes

1

answer

22

views

Sheldon Axler Measure Integration Real Analysis Section 2B Exercise 11

real-analysis measure-theory

modified 1 hour ago Oliver Diaz 7,170

1

vote

0

answers

10

views

Rearrangement of matrix inverse sum expression

matrices matrix-equations matrix-decomposition

asked 2 hours ago JDoe2 418

0

votes

1

answer

37

views

Calculate the total possible number of combinations out of x permutations, that's would sum to the same value.

combinatorics

modified 2 hours ago Nick Robinson 1

4

votes

0

answers

45

views

+50

Scaling of a matrix and its impact on eigen values

linear-algebra matrices reference-request eigenvalues-eigenvectors svd

modified 2 hours ago Alex Ravsky 62.8k

0

votes

0

answers

7

views

Normal bundle of immersed spheres

manifolds group-actions spheres fiber-bundles

asked 2 hours ago levitopher 2,343

7

votes

1

answer

820

views

How to choose contour in $\mathbb{C}$ to do Residue Integration.

integration complex-analysis reference-request

modified 2 hours ago Community♦ 1

5

votes

2

answers

32

views

Normal endomorphism on a group

abstract-algebra group-theory normal-subgroups

modified 2 hours ago k.stm 15.9k

0

votes

0

answers

28

views

How to optimize a high-order objective function?

optimization discrete-optimization

modified 2 hours ago Zistack 121

0

votes

0

answers

24

views

Rewrite $\int_{\mathbb{R^4}}\int_{\mathbb{R^4}}\ h(|x|^2,|y|^2,x\cdot y)\ dx\ dy$ as $\int\int\limits_{\Omega}\int\ J(u,v,w)\ h(u,v,w)\ du\ dv\ dw$.

real-analysis measure-theory lebesgue-integral fubini-tonelli-theorems

modified 2 hours ago Batominovski 46.2k

8

votes

0

answers

76

views

+50

Is $A$ ill conditioned matrix?

numerical-methods matrix-decomposition lu-decomposition

modified 2 hours ago André Armatowski 638

0

votes

0

answers

19

views

Naming of contravariant vector field and covariant vector field

differential-geometry

modified 2 hours ago Charlie Chang 353

0

votes

0

answers

11

views

Spectral gap of continuous-time Markov chain on nonnegative integers: The geometric long indel length chain

functional-analysis stochastic-processes markov-chains spectral-theory spectral-graph-theory

modified 2 hours ago xFioraMstr18 677

4

votes

0

answers

75

views

+50

Evaluating S depending upon following condition: Calculate the sum $S=\Sigma \Sigma \Sigma x_{i} x_{j} x_{k},$

sequences-and-series measure-theory summation solution-verification problem-solving

modified 2 hours ago Amartya Roy 1,538

0

votes

0

answers

21

views

Identify boolean function that satisfies some constrains

functions logic boolean-algebra constraints

modified 2 hours ago John 281

0

votes

0

answers

20

views

Identity related to $ \sum_{i=1}^{m}\sum_{j=i+1}^{m}\left\Vert a_i+a_j\right\Vert^2$

linear-algebra summation vectors

modified 2 hours ago 45465 173

-1

votes

0

answers

18

views

A puzzle on the hypercube

puzzle binary

asked 2 hours ago Ziofil 1,248

1

vote

0

answers

11

views

General solution form for Laplace equation in 3D

functions partial-differential-equations boundary-value-problem laplacian

asked 2 hours ago Indrasis Mitra 83

0

votes

1

answer

13

views

Determining analytically the number of times a line intersects a general 3D surface

geometry analytic-geometry 3d surfaces solid-geometry

modified 2 hours ago Robert Israel 383k

0

votes

0

answers

19

views

Does convergence imply uniform convergence in this example?

real-analysis sequences-and-series functional-analysis sequence-of-function

asked 2 hours ago Daniel Huff 90

0

votes

0

answers

17

views

Linear Independence for Subspaces

definition direct-sum

asked 2 hours ago Richard Costa 7

1

vote

0

answers

18

views

Simplification of an expression.

gamma-function products expression-simplification

modified 2 hours ago Mistos 706

2

votes

0

answers

22

views

Tic-tac-toe with one mark type

combinatorial-game-theory

asked 2 hours ago pi66 6,997

0

votes

0

answers

11

views

What's the expectation of a sum of product of couples of random variables?

probability statistics

asked 2 hours ago Enrico Milizia 21

3

votes

1

answer

40

views

How can I prove that $\sup(A) = \sup(B)$

logic power-series supremum-and-infimum

answered 2 hours ago cha21 511

2

votes

0

answers

28

views

Term for “field-like” algebraic object with infinitely-many “scaled” multiplication" operations parameterized by its elements?

abstract-algebra field-theory universal-algebra

asked 2 hours ago Mithrandir 84

0

votes

0

answers

7

views

Proof of infinite LU decompositions of $u e^t_i$

linear-algebra matrices induction lu-decomposition

asked 3 hours ago Alexander 93

2

votes

1

answer

39

views

Do the link cobordism induced maps on Khovanov homology for different diagrams commute?

low-dimensional-topology

answered 3 hours ago GageMartin 101

0

votes

0

answers

17

views

Extend a measure to a Radon measure

measure-theory geometric-measure-theory

asked 3 hours ago inbrevi 143

1

vote

0

answers

26

views

Prove the series converges almost everywhere

real-analysis sequences-and-series measure-theory lebesgue-integral

asked 3 hours ago Philip White 793

0

votes

0

answers

12

views

maximize area spanned by convex hull of a permutation.

convex-optimization convex-geometry convex-hulls

asked 3 hours ago peng yu 413

0

votes

0

answers

16

views

Prove that $E(N_t) = \frac{t}{E(Y_1)}$ for a renewal process

probability probability-theory stochastic-processes renewal-processes

asked 3 hours ago Euclid 3

0

votes

0

answers

11

views

How to know if two conic hull intersect

analytic-geometry

modified 3 hours ago miracle173 8,410

0

votes

0

answers

12

views

Riesz representation theorem on Hilbert spaces - validation of proof

functional-analysis hilbert-spaces riesz-representation-theorem

asked 3 hours ago Zxcvasdf 163

2

votes

0

answers

30

views

Can requirement on topology imply requirement on metric structure?

general-topology metric-spaces differential-topology

modified 3 hours ago Phun 121

0

votes

0

answers

15

views

FIxed Point Iteration (numerical analysis)

numerical-methods

asked 3 hours ago Mohit Sharma 21

2

votes

0

answers

22

views

Reducing a second order differential equation to first order system

calculus integration partial-differential-equations numerical-methods systems-of-equations

modified 3 hours ago MarshaT 21

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