Mathematics Stack Exchange

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votes

2

answers

13

views

To prove Inequality Question

inequality

answered 1 min ago Pegi 63

1

vote

1

answer

40

views

+50

Solution to the linear system $\dot u = Ju$ when $J$ has complex eigenvalues

matrices ordinary-differential-equations matrix-exponential

modified 1 min ago G. Gare 502

0

votes

0

answers

6

views

How to calculate the area enclosed by an implicit function?

area

asked 2 mins ago M.RaP_FreAk47 1

0

votes

1

answer

16

views

Supremum norm of a certain function in $C_{0}(\Omega)$

general-topology functional-analysis continuity banach-spaces supremum-and-infimum

answered 3 mins ago KeeperOfSecrets 166

1

vote

1

answer

35

views

Is i = 0 from Euler's Identity?

complex-numbers fake-proofs

answered 4 mins ago YiFan 9,045

0

votes

0

answers

7

views

Find the exponent with which $5$ is among the $1000!$

modular-arithmetic divisibility

asked 5 mins ago dumb_noob 40

0

votes

0

answers

3

views

Prove that a line is a polyhedron.

linear-algebra inequality linear-programming polyhedra

modified 13 secs ago Pegi 63

0

votes

1

answer

8

views

When is one allowed to merge “outside of integral” stuff inside integrals?

definite-integrals

answered 1 min ago Kabo Murphy 126k

0

votes

1

answer

23

views

$Ax = b$ has a solution for every $b$ if $A$ has a pivot in every row

linear-algebra proof-verification systems-of-equations gaussian-elimination

modified 10 mins ago Rodrigo de Azevedo 13.8k

0

votes

0

answers

11

views

Suppose $R$ is a partial order on set $A$, and $B \subseteq A$. Prove theorems about the uniqueness of the smallest element

proof-verification elementary-set-theory order-theory

modified 10 mins ago Rodrigo de Azevedo 13.8k

0

votes

0

answers

8

views

3blue1brown level for Devil's Calculator

recreational-mathematics education puzzle

asked 11 mins ago blindllama 1

1

vote

1

answer

21

views

Long exact sequence of derived functors from a finite exact sequence (resolution) ending with zeros

commutative-algebra homological-algebra derived-functors

answered 17 mins ago Jeremy Rickard 18.4k

4

votes

1

answer

41

views

Solving a “twisty puzzle” on $S_{20}$

group-theory permutations puzzle symmetric-groups

modified 18 mins ago Jean-Claude Arbaut 17k

1

vote

1

answer

20

views

Dividing Multivarate Gaussian Distributions

linear-algebra probability probability-distributions positive-definite

modified 18 mins ago scj 77

4

votes

1

answer

93

views

+50

How many solutions does $\lambda_1 e^{y - \lambda_1 e^y} (1 - \lambda_1 e^y ) + \lambda_2 e^{y - \lambda_2 e^y} (1 - \lambda_2 e^y ) = 0$ have?

calculus maxima-minima

answered 19 mins ago Cesareo 13k

0

votes

1

answer

25

views

Irreducible weight modules for sl2 which are not highest or lowest-weight

representation-theory lie-algebras

modified 20 mins ago Rafael Mrđen 1,144

0

votes

0

answers

9

views

Convergence of a “mixture” of convergent series

sequences-and-series convergence

asked 21 mins ago Lyuka 66

0

votes

2

answers

77

views

What are the rules of algebra within a real and complex functions $\Re(\cdot)$ and $\Im(\cdot)$?

real-analysis complex-analysis complex-numbers

answered 22 mins ago Dinno Koluh 146

0

votes

0

answers

4

views

What is the probability that the sum of points is equal to $6$ or the product is even number when we are rolling two dices?

probability

asked 22 mins ago Nikol Dimitrova 340

-1

votes

0

answers

9

views

If upper bound for chain doesn't exist, then that chain is infinite chain?

set-theory

asked 23 mins ago BlueHorn07 1

0

votes

2

answers

33

views

Taylor series and mean value theorem question: $f'(a)< f(a+1) -f(a) < f'(a+1)$ with $f''(x)>0$

calculus

answered 24 mins ago DanielWainfleet 39.3k

0

votes

1

answer

17

views

How to introduce sin as a function on real line to school students

trigonometry

answered 28 mins ago Olivier Roche 754

0

votes

0

answers

7

views

How can we show conditional indepedence here?

probability-theory conditional-expectation conditional-probability independence

asked 32 mins ago 0xbadf00d 1,362

0

votes

0

answers

28

views

How to prove uniqueness of the solution of a problem described?

real-analysis functional-analysis

modified 32 mins ago Rajesh Dachiraju 874

0

votes

0

answers

9

views

Proving the equality $\int |f|^p = \int_0^\infty pt^{p-1} \mu(\{x: |f(x)|\geq t\})) dt$ for $\sigma$-finite measure

real-analysis integration measure-theory lebesgue-integral norm

modified 33 mins ago The Bosco 713

0

votes

0

answers

5

views

Novice error while simplifying boolean expression with XOR

boolean-algebra

asked 36 mins ago XristosK 101

0

votes

0

answers

28

views

Show that $f$ attains a minimum at the origin.

analysis

modified 36 mins ago Xie 569

5

votes

1

answer

39

views

Show that there is no proper ideal of finite presentation of $R$.

abstract-algebra ring-theory commutative-algebra modules finitely-generated

answered 38 mins ago Minseon Shin 2,020

2

votes

0

answers

14

views

Behaviour of a sequence - how to fix this faulty proof?

calculus sequences-and-series functional-analysis inequality alternative-proof

asked 38 mins ago Jack D'Aurizio 302k

1

vote

0

answers

46

views

Who first defined functions as binary relations?

math-history

modified 40 mins ago Sergei Akbarov 953

0

votes

1

answer

5

views

Projections T/F

linear-algebra

answered 41 mins ago Kabo Murphy 126k

0

votes

0

answers

5

views

Disintegration of a push foward meausre.

probability-theory measure-theory pushforward

asked 42 mins ago CechMS 118

0

votes

0

answers

7

views

Coding a coordinate system rotation

coordinate-systems geodesy

asked 42 mins ago DrLeprikon 1

0

votes

1

answer

11

views

$L = \{(x,y) \in \mathbb R^{2} \mid x ≤ y \}$ and $C = \{x \in \mathbb R \mid x > 7 \}$, why $C$ doesn't have L smallest element?

elementary-set-theory

answered 44 mins ago Floris Claassens 4,016

1

vote

2

answers

41

views

Variation of $f(x)=x^2-\sqrt{x}$ over $(0;\infty)$ without using derivative (For student didn't get derivation method)?

real-analysis inequality calculus-of-variations a.m.-g.m.-inequality

answered 49 mins ago Raymond Manzoni 38k

0

votes

0

answers

8

views

What does mean for the restrictions to $U$ of maps of schemes to be equal?

algebraic-geometry schemes

asked 52 mins ago Johnny T. 649

1

vote

0

answers

15

views

Polynomial whose roots are some of the Nth-roots of unity.

number-theory elementary-number-theory complex-numbers roots-of-unity

asked 57 mins ago super_waqas 6

1

vote

0

answers

9

views

Probability of n events overlapping

probability-theory queueing-theory

modified 57 mins ago Stepan 538

0

votes

0

answers

11

views

Prove: $x \in \bar{B} \iff V \cap B \neq \emptyset \forall V \in Nbh(x)$

general-topology

modified 1 hour ago unknown333 16

0

votes

1

answer

83

views

Rademacher Complexity Result

probability-theory statistics machine-learning probability-limit-theorems upper-lower-bounds

modified 1 hour ago syeh_106 1,262

4

votes

1

answer

72

views

Find the number of different $10$ digit numbers having no digit repeated and divisible by $99$.

combinatorics elementary-number-theory

modified 1 hour ago Christian Blatter 184k

0

votes

1

answer

21

views

Matlab: Verifying an approximation is second order accurate

numerical-methods approximation matlab

answered 1 hour ago PierreCarre 4,034

3

votes

0

answers

34

views

+50

if such $(2n+4)x_{n+2}=b(2n+3)x_{n+1}+2a(n+1)x_{n}$ show $x_{n}\in Z$

sequences-and-series

modified 1 hour ago function sug 291

0

votes

0

answers

8

views

can the abel plana formula for riemann zeta function be solved?

riemann-zeta

asked 1 hour ago Rohan Asif 16

0

votes

0

answers

5

views

Adding inequaltiy contrains in ODE's using bvp4c in Matlab

ordinary-differential-equations constraints

asked 1 hour ago Damian 37

1

vote

1

answer

7

views

generator of ideal in ring of fraction

ring-theory ideals

answered 1 hour ago Berci 66.6k

1

vote

0

answers

27

views

Constructible numbers and triple angle formula

abstract-algebra geometric-construction

modified 1 hour ago Jean-Claude Arbaut 17k

0

votes

0

answers

44

views

A question on algebra

algebra-precalculus

modified 1 hour ago Ivan Neretin 9,652

0

votes

1

answer

21

views

If eigenvectors of different eigenvalues are orthogonal, then is the matrix normal?

eigenvalues-eigenvectors

answered 1 hour ago amd 37.8k

0

votes

0

answers

9

views

Finite mean and variance implies domain of normal attraction?

probability probability-limit-theorems

modified 1 hour ago Patrick Hew 802

0

votes

0

answers

7

views

Show that all Bessel functions of order 𝑛 satisfy the differential equation

ordinary-differential-equations

asked 1 hour ago aaa 1

0

votes

0

answers

12

views

if $f$ is $\mathcal{A}$-measurable, then it is also $\mathcal{A} \times \mathcal{B}$-measurable

real-analysis measure-theory proof-verification

asked 1 hour ago The Bosco 713

0

votes

0

answers

6

views

CTMC finding limiting distribution

statistics stochastic-processes markov-chains markov-process

asked 1 hour ago Wei Xiong Yeo 112

0

votes

1

answer

11

views

8 degrees of freedom in homography

projective-geometry computer-vision

answered 1 hour ago amd 37.8k

2

votes

1

answer

16

views

Presentation of $Q_{4n}$, $n \in \mathbb{N}$

abstract-algebra group-theory finite-groups group-presentation

answered 1 hour ago Mathematician 42 9,064

3

votes

0

answers

78

views

A real example of an Octonion product

octonions

modified 1 hour ago peawormsworth 126

0

votes

0

answers

13

views

Can I use Fubini-Tonelli on this integral?

integration lebesgue-integral

asked 1 hour ago Flintro 353

-1

votes

0

answers

6

views

universal normal representation of a von Neumann algebra

von-neumann-algebras

asked 1 hour ago S M 1

1

vote

2

answers

38

views

Compute the determinant of $A$

matrices determinant

modified 1 hour ago Rodrigo de Azevedo 13.8k

0

votes

0

answers

18

views

under-determined set of linear equations

linear-algebra geometry

asked 1 hour ago Gerhard 108

1

vote

0

answers

10

views

Can $L|K$ be a Galois extension if $\text {Fix}_{G}\ (L) = K$?

abstract-algebra ring-theory proof-writing field-theory galois-theory

modified 1 hour ago math maniac. 407

0

votes

1

answer

14

views

How to interpret this sample space set?

probability set-theory

answered 1 hour ago G. Gare 502

0

votes

1

answer

13

views

Multiple roots in Backward Euler Method

ordinary-differential-equations numerical-methods runge-kutta-methods

answered 1 hour ago G. Gare 502

0

votes

0

answers

8

views

Sets of harmonic measure zero

real-analysis brownian-motion potential-theory

modified 1 hour ago Henry 108k

0

votes

0

answers

6

views

Interval Exchange Transformation (IET) ergodicity

dynamical-systems ergodic-theory

asked 1 hour ago polbos 335

2

votes

1

answer

40

views

The set of points P for which PA/PA1+PB/PB1+PC/PC1=3.

geometry circles

modified 2 hours ago user21820 42.2k

4

votes

1

answer

20

views

Prove two linear functions cannot both be bounded.

functional-analysis analysis normed-spaces

modified 2 hours ago Mathematician 42 9,064

0

votes

0

answers

9

views

What sets of real numbers are definable in the language of real closed fields?

real-analysis field-theory first-order-logic real-numbers descriptive-set-theory

asked 2 hours ago Keshav Srinivasan 2,736

4

votes

0

answers

53

views

+50

Determine all functions $f:\mathbb{Z}\to\mathbb{Z}$ such that $f\big(f(n)\big)=-(q-p)\,f(n)+pq\,n$ for all $n\in\mathbb{Z}$.

functions recurrence-relations functional-equations recursion integers

modified 2 hours ago Batominovski 34.6k

0

votes

0

answers

12

views

straight line algorithm ellipse line drawing algorithm

algorithms

modified 2 hours ago David G. Stork 15.8k

0

votes

0

answers

7

views

Identify the faces, extreme points, and extreme rays of the polyhedral set

geometry convex-analysis linear-programming polyhedra

asked 2 hours ago Bilge 6

0

votes

0

answers

8

views

Fiber bundle of contractible sections

differential-geometry algebraic-topology lie-groups fiber-bundles

asked 2 hours ago AbdelRahman 11

3

votes

1

answer

35

views

+50

Show $\mathbb{Z}_{(p)} [ \sqrt{D}]$ is a UFD

ring-theory localization unique-factorization-domains quadratic-integer-rings

modified 2 hours ago msm 1,412

0

votes

1

answer

20

views

Prove that if $f$ is divisible by $h^2$ then h divides gcd(f,f')

polynomials ring-theory field-theory gcd-and-lcm

answered 2 hours ago Wuestenfux 11.9k

0

votes

0

answers

8

views

Lie derivative of a functional

differential-geometry lie-derivative

asked 2 hours ago amilton moreira 24

3

votes

2

answers

35

views

$f^n(x)$ where $n \in \mathbb{R}^+$

analysis

modified 2 hours ago alex.jordan 40.8k

5

votes

0

answers

25

views

There exists $2n-1$ pairs $(a_i, a_j)$ s.t. $a_i+a_j\geq 0$.

algebra-precalculus

asked 2 hours ago Problemsolving 1,036

0

votes

1

answer

161

views

prove $[Av]_s = P^{-1} AP[v]_s$

linear-algebra matrices

modified 2 hours ago eclmist 122

-1

votes

0

answers

5

views

Can a one-sided p-value ever be larger than a two-sided p-value?

probability statistics p-value

asked 2 hours ago John 49

6

votes

2

answers

79

views

If two functions are mirror images of each other about the line $y=x$, are they inverses of each other?

functions inverse inverse-function

answered 2 hours ago alex.jordan 40.8k

0

votes

0

answers

11

views

Which statistic can be calculated from others?

statistics

asked 2 hours ago TmTron 101

0

votes

1

answer

8

views

Congruent Prime Modulos

modular-arithmetic

answered 2 hours ago lab bhattacharjee 239k

0

votes

0

answers

10

views

Formulating a convex optimization problem as semidefinite program

optimization convex-optimization semidefinite-programming lmis schur-complement

modified 2 hours ago Rodrigo de Azevedo 13.8k

0

votes

0

answers

15

views

Non homogeneous boundary value problem

ordinary-differential-equations

modified 2 hours ago Syed Yunus Ali 16

1

vote

0

answers

22

views

Intersection of curve $ y = x^4 – 6x^3 + 12x^2 + cx + 1$

curves

asked 2 hours ago Samar Imam Zaidi 1,861

2

votes

0

answers

29

views

Sum of the digits in base $p+1$

number-theory elementary-number-theory prime-numbers

modified 3 hours ago Pruthviraj 448

0

votes

1

answer

7

views

The positive variation satisfies $\lambda^{+}=\sup\{\lambda (F) : F\subset E, F\in\chi \}$

analysis measure-theory measurable-sets

answered 3 hours ago Kabo Murphy 126k

0

votes

0

answers

7

views

Finding the constants in sigmoid equations

systems-of-equations curves regression regression-analysis

asked 3 hours ago Hussain-Alqatari 1,305

0

votes

0

answers

14

views

differential equation solving by integration method taking limit.

integration ordinary-differential-equations derivatives complex-integration

modified 3 hours ago b00n heT 11.5k

3

votes

1

answer

140

views

Formula for $\prod\limits_{k=-\infty}^\infty \frac{1}{e}\left(1+\frac{1}{k+z}\right)^{k+z+\frac{1}{2}}$

complex-analysis infinite-product

modified 3 hours ago user90369 9,665

0

votes

0

answers

9

views

How the tangent rotates when rotating a n-dimensional vector

geometry

asked 3 hours ago zhm1995 26

1

vote

0

answers

6

views

Show that $\langle \exp^{-1}_{x}(y), \exp^{-1}_{x}(y)\rangle_{g_{x}}=\langle \exp^{-1}_{y}(x), \exp^{-1}_{y}(x)\rangle_{g_{y}}$

differential-geometry riemannian-geometry geodesic

asked 3 hours ago Pablo_ 169

0

votes

1

answer

11

views

Check the convergence of the series $\sum (-1)^{n} n(1- \cos (a/n))$

sequences-and-series

answered 3 hours ago Doug M 46.5k

2

votes

1

answer

19

views

How do I prove $\mathcal{F} (e^{-\pi\alpha x^2}) =1/{\sqrt{\alpha}}e^{-\pi \xi^2 /\alpha}$ for $\alpha$ purely imaginary?

real-analysis fourier-analysis distribution-theory

modified 3 hours ago reuns 29.6k

1

vote

3

answers

29

views

Difference between Element and Element in braces in set

elementary-set-theory

answered 3 hours ago farruhota 26.4k

1

vote

1

answer

821

views

Homomorphic image of a PID

abstract-algebra ring-theory

modified 4 hours ago Megan 8

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