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2

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18

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Does $(AB)^m = I_n$ imply $(BA)^m = I_n$?

linear-algebra matrices group-theory

answered 10 secs ago student 1,459

2

votes

2

answers

54

views

Is there a way to prove that $A \setminus C = (A \setminus (B \cup C)) \cup ((A \cap B) \setminus C)$?

elementary-set-theory proof-writing

modified 1 min ago DonaldDuc 11

0

votes

0

answers

3

views

Finding E(XY|XY>E(X)E(Y))

normal-distribution expected-value

asked 2 mins ago actuarialSciStu 1

0

votes

1

answer

9

views

Find a sequence of $3$ tennis players such that their ratings are in increasing/decreasing order

combinatorics optimization

modified 3 mins ago S. Dolan 22.6k

0

votes

0

answers

11

views

Finding $A$, $B$, $C$ such that $(2x-A)(2x+4)-Bx+25=(x-C)^2-Cx^2$ for all $x$

algebra-precalculus

modified 4 mins ago Blue 62.9k

0

votes

1

answer

21

views

Does inverse property of a mathematical group require different elements X and Y?

group-theory analysis inverse

modified 5 mins ago Juan Castaño 525

0

votes

0

answers

9

views

How to prove that a variable can be defined implicitly from an equation?

real-analysis calculus

modified 5 mins ago Alon 1,537

12

votes

4

answers

996

views

The connection between decomposition of $\ker(f_\phi g_\phi)$ and the Chinese remainder theorem

linear-algebra ring-theory modules

modified 5 mins ago Marc van Leeuwen 100k

0

votes

1

answer

17

views

Can we say that this matrix is in row reduced echelon form?

matrices

modified 6 mins ago Stacker 3,139

0

votes

0

answers

30

views

predicate logic quesiton

logic predicate-logic

modified 7 mins ago Mauro ALLEGRANZA 83.2k

0

votes

1

answer

9

views

CDFs of indicator random variables

probability probability-distributions

modified 7 mins ago Kavi Rama Murthy 246k

0

votes

0

answers

5

views

Proof that $\bigcup_{i \epsilon I} A_{i}$ is an elementary substructure of $\mathfrak{U}$

solution-verification set-theory model-theory

modified 9 mins ago Vagoltof 1

0

votes

0

answers

16

views

Proof that $\sum_{k=1}^n \frac{k}{2^k} < 2 $ for all $n \geq 1$

inequality summation solution-verification contest-math riemann-sum

asked 9 mins ago Darrell Tan 87

0

votes

3

answers

33

views

Need help solving this log equation $\log_{5}(x-4) = \log_{10}(x+5)$

logarithms

answered 10 mins ago Claude Leibovici 181k

0

votes

3

answers

13

views

Rank-Nullity Possible Pairs

linear-algebra matrices linear-transformations matrix-rank

answered 11 mins ago Stacker 3,139

0

votes

3

answers

15

views

Find the range of $f:(-4,6) \rightarrow R$ , $f(x):x^2 -4x +1$

algebra-precalculus functions inequality

modified 14 mins ago José Carlos Santos 317k

0

votes

0

answers

8

views

Probability of exactly k runs of wins

probability combinatorics

asked 14 mins ago Sukti Sen 13

0

votes

2

answers

21

views

Given a set of m numbers {1,2,…m} we can always select a subset having sum of [1,m(m+1)/2]

combinatorics number-theory

answered 40 secs ago bof 64.9k

0

votes

0

answers

8

views

Proof verification for Rotman Exercise 6.7 (barycentric subdivision when $n=1$)

algebraic-topology solution-verification

asked 18 mins ago boink 1,105

1

vote

1

answer

17

views

Finding the eigenvalue of F(V)=(V⋅W)W+V where W=(1 , 1 , 2) and f:R^3 → R^3

linear-algebra

answered 19 mins ago Vajra 1,413

1

vote

1

answer

13

views

Divergence theorem: compute triple integral over a paraboloid between two planes

integration multivariable-calculus solution-verification volume divergence-theorem

modified 20 mins ago Math Lover 15k

0

votes

0

answers

2

views

Finite difference with lexicographic ordering

finite-differences finite-difference-methods

asked 20 mins ago kashif iqbal 1

0

votes

1

answer

969

views

Projectile with air drag using MATLAB

matlab projectile-motion

modified 21 mins ago Community♦ 1

-1

votes

1

answer

10

views

Hypothesis test concerning a population mean

probability-distributions

answered 22 mins ago Stacker 3,139

0

votes

0

answers

5

views

Let $f:R^k \to R, k \geq 2$ Partial function, continuous in punctured neighborhood of $a \in R^k$ Prove $f$ Is not one-to-one

real-analysis calculus

asked 24 mins ago Alon 1,537

3

votes

1

answer

22

views

Find the Laplace $\mathcal{L}(y(t))$ if $y'(t)-y(t)+\int_0^t y(u)e^{\alpha(t-u)}du=\alpha e^{\alpha t}$

laplace-transform

modified 31 mins ago Alex 3,193

1

vote

1

answer

283

views

Reduction from 3SAT to NAE3SAT

np-complete satisfiability

answered 31 mins ago gautam 153

2

votes

1

answer

22

views

Distributing 4 distinct balls into 3 distinct bins($bin_1,bin_2,bin_3$) , such that $bin_2$ always has a ball

combinatorics permutations solution-verification

answered 33 mins ago Henno Brandsma 189k

1

vote

0

answers

15

views

Prove that there exists at least a form $g\left ( a, b, c \right )\pm f\left ( a, b, c \right )\left ( a- b \right )\left ( b- c \right )$ of $H$

optimization terminology intuition sums-of-squares research

modified 37 mins ago haidangel 487

0

votes

1

answer

12

views

Linear operator that commutes with projection

linear-algebra vector-spaces linear-transformations

answered 38 mins ago Danny Pak-Keung Chan 7,120

0

votes

1

answer

20

views

Proving that a proposition is a theorem in $L_I$.

logic propositional-calculus

modified 39 mins ago Mauro ALLEGRANZA 83.2k

0

votes

1

answer

20

views

open balls cover function space

general-topology

answered 39 mins ago Henno Brandsma 189k

1

vote

1

answer

23

views

Parametrising $\mathbb{R^3}$ coordinates using a mesh with barycentric coordinates, and signed distance to the mesh

linear-algebra geometry barycentric-coordinates

modified 43 mins ago brainjam 3,916

2

votes

0

answers

14

views

Linear-order sets isomorphism

elementary-set-theory set-theory order-theory

modified 48 mins ago William Elliot 16.5k

2

votes

2

answers

35

views

Does the following necessarily converge to a normal random variable in distribution?

probability-theory probability-distributions convergence-divergence weak-convergence central-limit-theorem

modified 56 mins ago StubbornAtom 12.8k

0

votes

0

answers

14

views

Is there any method to solve this probability and find an closed form expression?

probability-theory probability-distributions random-variables exponential-distribution probability-limit-theorems

asked 57 mins ago Rahul 1

0

votes

1

answer

23

views

2000 people play chess, need to find the maximal number of games during the marathon if…

graph-theory

answered 1 hour ago Ross Millikan 350k

2

votes

2

answers

16

views

Show limit point of product topology and sequence converging to $0$

general-topology solution-verification

answered 1 hour ago Danny Pak-Keung Chan 7,120

0

votes

0

answers

6

views

Determine the partial fraction convolution output y(ω) signal using fourier transform.

fourier-transform convolution signal-processing discrete-time

asked 1 hour ago Rane 1

1

vote

1

answer

19

views

What is the geometric difference between the eigenvectors and eigenspace of a 3x3 matrix?

linear-algebra

answered 1 hour ago S. Dolan 22.6k

0

votes

0

answers

18

views

how to find limits of integration

integration multivariable-calculus multiple-integral

asked 1 hour ago Blake 45

0

votes

0

answers

12

views

Upper bounds for a sequence of integers defined recursively

catalan-numbers integer-sequence growth-rate

asked 1 hour ago guacho 1,292

2

votes

2

answers

34

views

Given an arbitrary quadratic polynomial $ax^2 + bx + c$, how do I find the path the vertex of the parabola travels upon when b is varied?

polynomials conic-sections

answered 1 hour ago heropup 92.3k

1

vote

2

answers

1k

views

Regular polygons that touching to a sphere surface

geometry 3d polyhedra

answered 1 hour ago David Cary 1,737

4

votes

1

answer

73

views

+50

What's the intuition behind the Co-Area formula?

measure-theory multivariable-calculus differential-geometry differential-topology geometric-measure-theory

answered 1 hour ago Deane 456

0

votes

0

answers

8

views

Is $\mathfrak L_1(X,Y)'=\overline{\operatorname{span}\left\{x\otimes\varphi:(x,\varphi)\in X\times Y'\right\}}$?

functional-analysis operator-theory banach-spaces tensor-products trace

asked 1 hour ago 0xbadf00d 11.4k

0

votes

1

answer

15

views

Equivalent conditions for $M$-genericity

set-theory forcing

modified 1 hour ago Noah Schweber 189k

1

vote

0

answers

21

views

Let $A ⊆ E ⊆ R$, where $E$ is measurable and $A$ is non-measurable. Prove that $m^∗ (E − A) > 0$

measure-theory lebesgue-integral lebesgue-measure

modified 1 hour ago John Samples 1,489

1

vote

1

answer

18

views

For the value iteration function, if the immediate cost is a linear function in state, then is this value iteration function convex?

discrete-mathematics convex-analysis convex-optimization linear-programming dynamic-programming

modified 1 hour ago Michael Jackson 23

0

votes

3

answers

82

views

Finding the absolute maximum and minimum of a function in a disk?

multivariable-calculus

answered 1 hour ago boojum 165

0

votes

0

answers

18

views

How to solve the heat PDE with a dirac delta in the boundary condition?`

partial-differential-equations dirac-delta

asked 1 hour ago megamence 235

0

votes

0

answers

25

views

Name for operation with property x # x = x

terminology binary-operations associativity

asked 1 hour ago Kevin the frog 11

0

votes

1

answer

21

views

Essential requirements for the definition of a function.

elementary-set-theory

answered 1 hour ago William Elliot 16.5k

0

votes

0

answers

10

views

How to evaluate cumulative distribution function w/ sigma of given SRS?

statistics

modified 1 hour ago TheFiveHundredYears 3

0

votes

1

answer

14

views

Prove that, there does not exist any $A ⊆ R$ satisfying $m(A ∩ I) = α l(I)$, for all intervals $I ⊂ R$

measure-theory lebesgue-measure

modified 1 hour ago Kavi Rama Murthy 246k

0

votes

0

answers

26

views

Given the coordinates of two convex polygons, is there any formula to calculate the percentage overlap between them?

geometry recreational-mathematics area polygons

modified 1 hour ago Kristada673 495

4

votes

2

answers

76

views

$\int_0^{2 \pi} \sinh^{-1} \left( \frac{h}{\sqrt{s^2 + R^2 -2sR \cos(\phi)}} \right) d \phi $

integration definite-integrals trigonometric-integrals

answered 1 hour ago Claude Leibovici 181k

0

votes

0

answers

14

views

How can i predict how many participants i will need in hypothesis test trial?

statistics hypothesis-testing

asked 1 hour ago Alon 1,537

0

votes

0

answers

28

views

Count the number of ways

combinatorics

modified 1 hour ago Reneo 171

1

vote

0

answers

12

views

Problem conditions to use Laplacian solvers

linear-algebra graph-theory graph-laplacian

asked 1 hour ago Mah 1,039

0

votes

1

answer

15

views

What is the right ball-park in a sub-space?

analysis

answered 2 hours ago Arun Bharadwaj 156

-1

votes

0

answers

14

views

conformal mapping - complex analysis

complex-analysis conformal-geometry

asked 2 hours ago Samar Hayek 147

1

vote

0

answers

14

views

How to find variance of the entries in this matrix?

matrices expected-value variance

asked 2 hours ago MaxFrost 15

0

votes

0

answers

12

views

Mean curvature vector

differential-geometry riemannian-geometry

asked 2 hours ago z.z 83

1

vote

0

answers

23

views

Cauchy criterion problem

real-analysis sequences-and-series proof-writing

asked 2 hours ago Kraftsman 563

4

votes

1

answer

21

views

Filling a Board with Tiles that can be overlapped

combinatorics tiling

answered 2 hours ago RavenclawPrefect 6,851

-1

votes

0

answers

30

views

Formula about measure theory (not 100% sure) in a spatial knowledge economic model

measure-theory economics

modified 2 hours ago metamorphy 22.6k

1

vote

0

answers

19

views

+50

Write output of linear dynamical system in terms of adjugate matrix

dynamical-systems laplace-transform

modified 2 hours ago LetterSized 73

1

vote

2

answers

16

views

Gradient of function that can be expressed as another function

gradient-descent

modified 2 hours ago Shubham Johri 15.3k

0

votes

1

answer

21

views

Jacobian matrix of a composition of functions with chain rule

linear-algebra ordinary-differential-equations machine-learning jacobian

answered 2 hours ago GReyes 9,251

2

votes

1

answer

19

views

Equivalence of $R$-linear categories are $R$-linear?

category-theory modules functors additive-categories

answered 2 hours ago Eric Wofsey 262k

1

vote

1

answer

30

views

Probability of CDC data

probability statistics

answered 2 hours ago Stacker 3,139

0

votes

0

answers

9

views

Filling a n by n matrix with 1's and 0's under specific conditions

linear-algebra combinatorics matrices group-theory

asked 2 hours ago BooleanWick 1

2

votes

2

answers

22

views

Given a k-algebra A, representations $V, W$ of $A$, and homomorphism $\phi: V \rightarrow W,$ prove that ker$\phi$ is a subrepresentation of $A$

representation-theory

answered 2 hours ago Joshua P. Swanson 4,589

1

vote

0

answers

14

views

Without the CS inequality, if the infinite series of the sequence (x_n^2)/n converges, & if X_n is the sequences of averages, show the limit Xn = 0.

real-analysis calculus sequences-and-series analysis

asked 2 hours ago mediocremathstudent 33

6

votes

1

answer

34

views

Given $\sigma$ a coprime automorphism of $G$ a finite group, must the centre of $G^\sigma$ be contained in the centre of $G$?

group-theory finite-groups group-isomorphism

modified 2 hours ago Arturo Magidin 324k

1

vote

0

answers

11

views

Understanding domain and range of a Tensor as an operator

matrices vector-spaces tensors multilinear-algebra

asked 2 hours ago Abhi_P 11

0

votes

2

answers

29

views

Equivalence class for a determinant

abstract-algebra matrices equivalence-relations

answered 2 hours ago Hamdiken 78

0

votes

1

answer

21

views

Why is an affine translation said to be a shear in a higher dimension?

linear-algebra matrices vectors linear-transformations

answered 2 hours ago GReyes 9,251

-1

votes

0

answers

7

views

How to count reducible expressions?

lambda-calculus

asked 2 hours ago user889407 1

0

votes

0

answers

14

views

Showing this multivariable function is uniformly continuous

analysis multivariable-calculus continuity uniform-continuity

modified 2 hours ago Ralph 3

0

votes

1

answer

23

views

Help needed with minimum cost flow problem

optimization operations-research network-flow

modified 2 hours ago RobPratt 21.4k

2

votes

0

answers

18

views

Definition of Cofinality Motivation

set-theory cardinals ordinals

asked 3 hours ago BENG 807

1

vote

1

answer

18

views

Do the genus, codimension and projective space weights determine a Fano threefold?

algebraic-geometry complex-geometry birational-geometry projective-varieties

answered 3 hours ago Sasha 9,428

1

vote

0

answers

15

views

Properties of supremum of $2$ sets versus supremum of $2$ functions

real-analysis

modified 3 hours ago Ricky_Nelson 1,368

1

vote

0

answers

13

views

Arrangements of $5$ A's,$7$ B's and $4$ C's to form a $16$ letter word so that there are at least $3$ $CA$ pairs occurring in the word.

combinatorics discrete-mathematics permutations combinations

asked 3 hours ago Maverick 5,675

2

votes

0

answers

30

views

What is the point of giving a tensor identity in normal coordinates?

differential-geometry riemannian-geometry coordinate-systems tensors curvature

modified 3 hours ago piRskwayrd 53

5

votes

0

answers

146

views

Hatcher 3.3 Exercise 6

algebraic-topology

modified 3 hours ago Jack Kennedy 1

1

vote

1

answer

19

views

Limit carries with e proof

real-analysis limits solution-verification

answered 4 hours ago Paramanand Singh 71.1k

1

vote

0

answers

4

views

From representations of $SL(2)$ to representations of $SL(2)^\pm$

representation-theory

asked 4 hours ago Wirdspan 367

0

votes

1

answer

18

views

Does ||Tx||=||T*x|| all x imply normality for real Hilbert spaces?

linear-algebra hilbert-spaces

answered 4 hours ago Etienne 1

0

votes

0

answers

6

views

Hypergeometric differential equation for c=1 and a+b+1=0

ordinary-differential-equations hypergeometric-function

asked 4 hours ago user630770 19

0

votes

1

answer

2k

views

Hypothesis Test with Uniform Distribution

uniform-distribution hypothesis-testing

modified 4 hours ago Community♦ 1

2

votes

1

answer

147

views

+50

Reference for Exercise 5.3.1 in [Probability: Theory and Examples, 4th edition, Durrett, 2010]

probability probability-theory stochastic-processes martingales stochastic-analysis

modified 4 hours ago Nuno 678

2

votes

0

answers

21

views

A power series equality involving binomial coefficients

combinatorics power-series binomial-coefficients

asked 4 hours ago asahay 176

-3

votes

4

answers

109

views

If $x+y=2$ then show that $x^2y^2(x^2+y^2)≤2$

proof-verification inequality

answered 4 hours ago Martund 11.9k

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