Mathematics Stack Exchange

0

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1

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9

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Example of Weierstrass Polynomial Approximation Theorem?

real-analysis

answered 53 secs ago Ian 84k

4

votes

4

answers

746

views

Self contained reference for norm and trace

abstract-algebra reference-request

modified 1 min ago KCd 25.1k

0

votes

0

answers

4

views

There are 10 speakers in a conference $S_1, S_2..S_{10}$ and $S_1$ speaks only after $S_2$ has spoken…

permutations

asked 2 mins ago Aditya 5,297

0

votes

0

answers

2

views

Type of distribution and mgf

probability probability-distributions

asked 2 mins ago Kraftsman 879

0

votes

0

answers

10

views

Possible Error in the 1990 B1 Putnam Answer Key

integration contest-math

asked 3 mins ago JPwin 91

0

votes

0

answers

3

views

Finding the conditional multinomial distribution $ \mathbf{P}(X_1=t_1,…,X_k=t_k|X_{k+1} = s_1, . . . , X_{n−1} = s_{n−k+1})$

probability statistics probability-distributions conditional-probability

asked 4 mins ago strawberry-sunshine 4,161

0

votes

0

answers

2

views

Conditions of a parametric curve symmetric about coordinate axes

calculus curves parametric

asked 5 mins ago abcdmath 1,147

1

vote

0

answers

10

views

Using Cholesky Decomposition iteratively to find eigenvalues

linear-algebra eigenvalues-eigenvectors numerical-linear-algebra cholesky-decomposition

modified 6 mins ago RobPratt 21.7k

0

votes

0

answers

4

views

Understanding the Jacquet module of $GL_2(\mathbb{F}_q)$

representation-theory finite-fields general-linear-group

asked 6 mins ago JLF 123

1

vote

0

answers

44

views

Čech cohomology with values in a locally trivial presheaf

algebraic-topology sheaf-theory sheaf-cohomology

modified 6 mins ago Huanghow 33

1

vote

1

answer

14

views

What is an example of a discontinuous function from $\mathbb{R}^{\omega}$ such that sequential limit is preserved?

general-topology

answered 6 mins ago Brian M. Scott 558k

0

votes

1

answer

11

views

Proof of Folland Lemma 3.2

measure-theory

answered 7 mins ago Ramiro 11.2k

1

vote

0

answers

3

views

Let $\pi$ be the projection map $\pi:\mathbb{S}^2 \to \mathbb{R}P^2$, does $\pi$ have a smooth inverse?

differential-geometry manifolds smooth-functions

asked 8 mins ago Emilio Volpe 11

0

votes

0

answers

2

views

Suppose that y1 = 8.3, y2 = 4.9, y3 = 2.6, y4 = 6.5 is a random sample of size 4 from the two parameter uniform pdf,

statistics density-function moment-generating-functions

asked 11 mins ago David Nam 31

-2

votes

1

answer

11

views

4 digit code probability

probability permutations combinations

answered 11 mins ago Amaan M 1,896

8

votes

1

answer

107

views

Show there exists no diffeomorphism between positive real line and a spiral

analysis derivatives differential-geometry differential-topology

modified 12 mins ago Matematleta 24.4k

0

votes

1

answer

17

views

Rudimentary Infinite Series question

calculus

modified 13 mins ago no lemon no melon 1,291

2

votes

0

answers

7

views

Shuffling items between two boxes

probability probability-theory

asked 16 mins ago Randy Dennis Retherford 215

0

votes

0

answers

5

views

is every edge of a zonotope a generator?

convex-geometry polytopes discrete-geometry

asked 16 mins ago peng yu 597

-2

votes

1

answer

16

views

Rolling a die. Math problem

probability combinatorics probability-theory statistics discrete-mathematics

answered 18 mins ago Aditya Dwivedi 1,251

0

votes

1

answer

11

views

Zeroes of $x^{p^n} - x$ are distinct in splitting field of $\mathbb{F}_p$

field-theory galois-theory splitting-field

answered 22 mins ago KCd 25.1k

1

vote

1

answer

20

views

Is the image of closed unit ball under the linear operator closed?

functional-analysis banach-spaces compact-operators adjoint-operators

answered 29 mins ago thing 1,265

1

vote

0

answers

48

views

Is There an Abel-plana-type Exact Formula for the Imaginary Part of the Oscillatory Integral over Exp(iπx)x^(1/x) Between 1 and Infinity?

sequences-and-series definite-integrals improper-integrals

modified 30 mins ago Marvin Ray Burns 267

5

votes

1

answer

106

views

Determining a polynomial $p$ from its image of rationals.

abstract-algebra polynomials rational-numbers

modified 32 mins ago Viktor Vaughn 15.7k

0

votes

1

answer

23

views

Express a problem as function/sets

combinatorics discrete-mathematics functions elementary-set-theory permutations

modified 33 mins ago zzzz zazaza 23

1

vote

0

answers

11

views

Aproximating function by polynomials of degree at least $2$.

real-analysis polynomials uniform-convergence

asked 34 mins ago Carlos Jiménez 3,244

0

votes

0

answers

8

views

representable functors and finitely generated algebras

algebraic-geometry commutative-algebra representable-functor

asked 36 mins ago S.Gau at Math 750

0

votes

0

answers

8

views

Why the limit of $\sqrt{n}$ sample variance is variance?

statistics normal-distribution

asked 36 mins ago Yichuan 1

1

vote

1

answer

21

views

Give an example of sets $E_n$ that satisfy part (a) and also satisfy $\bigcap^\infty_{n=1} E_n= \emptyset$

analysis cauchy-sequences

modified 37 mins ago J. W. Tanner 54.6k

0

votes

0

answers

17

views

Cosine Series of $-\frac{1}{5}\sin x$ on $[0,\pi]$

calculus partial-differential-equations fourier-series

modified 37 mins ago Amaan M 1,896

0

votes

0

answers

5

views

What's the uncertainty on the standard deviation for grouped data?

standard-deviation descriptive-statistics

asked 38 mins ago jackzip 13

0

votes

0

answers

16

views

(Linear Algebra) What is a fixed polynomial of degree 2?

polynomials

asked 40 mins ago BrodinRoden 1

2

votes

0

answers

12

views

Let $n=pq,$ where $p$ and $q$ are distinct primes. How many numbers $a \in \{1, 2, …, n\}$ satisfy $a^{n-1} = 1 \mod n$?

number-theory

modified 41 mins ago haidangel 1,530

0

votes

0

answers

16

views

For a given function $f: [3, 4] \to \mathbb{R}$ we define the function g by a rule $g(x) = f(x+x^{-1})$

real-analysis

asked 42 mins ago Niki Sedlarević 369

1

vote

0

answers

16

views

Show that $m^{}([a, b]\backslash G)=b − a- m^{}{(G)}$

measure-theory proof-explanation lebesgue-measure outer-measure

modified 42 mins ago haidangel 1,530

0

votes

0

answers

5

views

finer topology and topology induced by norms

general-topology metric-spaces matrix-norms

asked 42 mins ago ask 1234 71

1

vote

1

answer

33

views

Are periodic tilings stable against defects outside of some region away from the defect?

discrete-mathematics reference-request tiling

modified 43 mins ago RavenclawPrefect 7,983

1

vote

0

answers

9

views

Independent probabilities of four events

probability probability-distributions

asked 44 mins ago Lilian Crow 67

6

votes

1

answer

115

views

+50

Proving a functional inequality in dimension 1

inequality functional-inequalities

modified 44 mins ago haidangel 1,530

0

votes

1

answer

58

views

Why my this formula doesn't satisfy the formula of volume of sphere?

integration geometry systems-of-equations spheres

modified 45 mins ago eordo 26

0

votes

0

answers

14

views

Closure of the image of generic point

algebraic-geometry

asked 49 mins ago finiteness 719

0

votes

1

answer

14

views

Find the equation to the tangent to the curve $y=x^3$ at point (2,8)

calculus

answered 51 mins ago Wynne Liu 39

0

votes

0

answers

8

views

Show that this set of equations has no real solutions

systems-of-equations

asked 51 mins ago justadumbguy 97

1

vote

2

answers

16

views

Show Lipschitz condition for $f(x) = x+|x|$

lipschitz-functions

modified 51 mins ago DalatKarelia 815

0

votes

0

answers

7

views

Proof that the greedy for minimum coin change is correct

discrete-mathematics algorithms induction data-structure

asked 52 mins ago ǝrroɹ 27

0

votes

0

answers

8

views

How can I show that an element does not belong to a certain ideal?

abstract-algebra ring-theory ideals

asked 53 mins ago Akash Narayanan 1

0

votes

0

answers

4

views

are the solutions to a continuous piecewise quadratic equation necessarily also continuous and piecewise?

piecewise-continuity implicit-function

asked 54 mins ago Ack 1

1

vote

1

answer

14

views

Prove GCD statement with multiple variables

proof-writing induction gcd-and-lcm integers

answered 56 mins ago fleablood 110k

0

votes

1

answer

21

views

Colouring of lines in a polygon to find relations between people at a party

combinatorics graph-theory coloring

modified 59 mins ago RobPratt 21.7k

1

vote

0

answers

17

views

If $G$ is a connected graph, then $G$ contains an Euler circuit if and only if every vertex has even degree (Misunderstanding of terminology).

graph-theory eulerian-path

modified 1 hour ago RobPratt 21.7k

0

votes

0

answers

8

views

Analytic methods of computing entrywise absolute values of matrices

linear-algebra matrices

modified 1 hour ago Jandré Snyman 520

1

vote

1

answer

23

views

Representations of a semigroup over a Hilbert space

operator-algebras c-star-algebras semigroups semigroup-of-operators noncommutative-geometry

modified 1 hour ago Ruy 9,013

1

vote

0

answers

11

views

Set up an iteration scheme to solve $\frac{{\rm d}x}{{\rm d}t}= tx^{2}+ x^{3}, x(0)= 1,$ take $\delta< 1/5$

analysis

modified 1 hour ago haidangel 1,530

1

vote

0

answers

27

views

How can I prove that this language is context free?

discrete-mathematics regular-language context-free-grammar

modified 1 hour ago haidangel 1,530

2

votes

0

answers

106

views

+50

Two problems involving a symmetric non–negative polynomial on subset $\left [ 1, 2 \right ]^{3}$

terminology problem-solving intuition substitution functional-inequalities

modified 1 hour ago haidangel 1,530

1

vote

0

answers

9

views

Definite integrals and infinite sums with known (conjectured) closed forms but no proof

sequences-and-series definite-integrals closed-form

asked 1 hour ago Pavlo. B. 11

0

votes

1

answer

20

views

How many outcomes are possible?

probability combinatorics probability-theory statistics discrete-mathematics

answered 1 hour ago chary 21

0

votes

1

answer

26

views

Uniform Problem - Expected Value

probability-theory probability-distributions uniform-distribution

modified 1 hour ago BruceET 45.1k

0

votes

0

answers

28

views

$A$ is $p\times n$, $B$ is $q\times n$, what can we say about Systems $1$ and $2$ of equations?

linear-algebra matrices systems-of-equations

modified 1 hour ago strawberry-sunshine 4,161

0

votes

0

answers

9

views

Do I need to convert a data set into a probability distribution before feeding it into a Monte Carlo simulation?

sampling monte-carlo

modified 1 hour ago Gili 141

1

vote

0

answers

5

views

How to count/enumerate equivalent colorings

combinatorics group-theory set-theory equivalence-relations polya-counting-theory

asked 1 hour ago dimoxinil 11

1

vote

2

answers

24

views

Use Schur to prove that for any norm $\lim_{n \rightarrow \infty} ||A^n|| = 0 \text{ iff } \rho(A) < 1$ where $\rho$ denotes spectral radius.

linear-algebra numerical-linear-algebra

answered 1 hour ago user1551 108k

0

votes

2

answers

18

views

In a formal axiomatic system with both the law of the excluded middle and the axiom of infinity does an uncountable set have to exist?

elementary-set-theory infinity axioms

answered 1 hour ago Eric Wofsey 263k

0

votes

0

answers

27

views

Why not the easier format for the derivatives of inverse functions

algebra-precalculus trigonometry soft-question inverse

modified 1 hour ago Light Yagami 3,305

0

votes

0

answers

10

views

Commutative Hopf algebra as a smash product

hopf-algebras algebras quantum-groups

modified 1 hour ago JPhy 1,385

1

vote

0

answers

24

views

Getting Mixed Up With Limit Notation and Sequence Notation.

real-analysis

asked 1 hour ago GrayLiterature 209

2

votes

1

answer

20

views

Why do these two equivalent equations have different implicit differentiations?

calculus derivatives implicit-differentiation

modified 1 hour ago DMcMor 7,364

0

votes

0

answers

3

views

Determine whether one to one or onto (with indicator function)

functions

asked 1 hour ago noch 1

1

vote

1

answer

30

views

Unique solution in a quasi-convex optimization problem?

optimization convex-analysis convex-optimization non-convex-optimization

answered 1 hour ago asun 106

3

votes

1

answer

33

views

Axiomatic proof in S4

answered 1 hour ago Alex Kruckman 47.5k

0

votes

0

answers

14

views

The genus of the following algebraic curve(tetragonal curve)

algebraic-geometry algebraic-curves riemann-surfaces

asked 1 hour ago Jia Minxin 31

0

votes

0

answers

13

views

how to model introduction of wolves to population growth model for deer?

calculus integration differential

asked 1 hour ago tom 3

0

votes

1

answer

15

views

How do I prove that the cross product follows the right hand rule for vectors in the xz plane?

proof-explanation cross-product

answered 1 hour ago David K 75.6k

0

votes

1

answer

16

views

Why does the fixed point method rely on the derivative of the root for convergence or divergence?

numerical-methods fixed-point-theorems

answered 1 hour ago aschepler 2,572

3

votes

0

answers

50

views

+100

For a non-vanishing field $X$ and $a\in C^1(\mathbb R^n;\mathbb C)$, how to reduce the study of $X\cdot \nabla u +au= f$ to the study of $Xv=g$?

real-analysis complex-analysis partial-differential-equations characteristics hyperbolic-equations

modified 1 hour ago Calvin Khor 26.3k

-1

votes

0

answers

18

views

build a population growth model

complex-analysis

modified 1 hour ago Henry Pang 1

1

vote

0

answers

7

views

The Cross Ratio of a Mobius Transformation - Definition Clarification

complex-analysis conformal-geometry mobius-transformation

asked 1 hour ago eightc 258

0

votes

0

answers

9

views

Feature of Graph Laplacian matrix to draw a tetrahedron mesh without plan cross?

graph-theory manifolds convex-optimization planar-graphs graph-laplacian

asked 1 hour ago ES_YD 1

0

votes

0

answers

11

views

Proving the boundedness property of the poisson kernel

fourier-analysis fourier-series

modified 1 hour ago cabmetric 65

2

votes

0

answers

18

views

Evaluating an adelic integral

integration number-theory adeles

modified 1 hour ago Wirdspan 367

0

votes

0

answers

6

views

Matrix normal, then is the same true for the fundamental system?

ordinary-differential-equations analysis dynamical-systems fundamental-solution

modified 2 hours ago amsmath 8,772

3

votes

1

answer

38

views

$3\times3$ grid filled in randomly; probability of a $2\times2$ grid filled with one element

probability independence

modified 2 hours ago Laufen 1,153

2

votes

0

answers

7

views

Measure of time spent increasing by a diffusion

stochastic-processes stochastic-calculus brownian-motion stochastic-integrals

asked 2 hours ago 900edges 413

0

votes

1

answer

13

views

Find a formula for leaves in tree

discrete-mathematics graph-theory induction trees data-structure

answered 2 hours ago Brian M. Scott 558k

0

votes

2

answers

35

views

1. a. Given that $y= \sqrt{4x^2- 7},$ show that $y\frac{{\rm d}y}{{\rm d}x}= 4x$

calculus

modified 2 hours ago haidangel 1,530

0

votes

0

answers

11

views

Showing that the theory of an infinite descending $\subseteq$ chain has Morley rank 2

logic model-theory

asked 2 hours ago ikrto 469

1

vote

0

answers

17

views

Consistency in Statistical Decision Theory

probability-theory statistics decision-theory

modified 2 hours ago lmaosome 385

0

votes

0

answers

8

views

Transform point in the Poincaré disc to point in tile

transformation hyperbolic-geometry tiling

asked 2 hours ago HelloGoodbye 281

1

vote

0

answers

13

views

Do “the ratio of A to B” and “A:B” always mean A/B as a fraction?

definition ratio

asked 3 hours ago user13651701 21

0

votes

0

answers

20

views

Proof check: Divided difference is exactly the coefficient of the interpolation polynomial (in Newton basis)

numerical-methods solution-verification

modified 3 hours ago LHC2012 577

3

votes

0

answers

45

views

Writing a given process as a diffusion

probability stochastic-processes stochastic-calculus poisson-process

modified 3 hours ago 900edges 413

0

votes

0

answers

23

views

Non-semi-simple finite-dimensional algebras

abstract-algebra ring-theory examples-counterexamples noncommutative-algebra algebras

modified 3 hours ago Eric Wofsey 263k

0

votes

0

answers

15

views

apply ode technique to find the Fourier transform

fourier-transform

modified 3 hours ago Bernard 163k

3

votes

0

answers

125

views

+50

If $x,y,z>0$, prove that: $\frac{x}{y+z}+\frac{y}{x+z}+\frac{z}{x+y}\ge \sqrt{2}\sqrt{2-\frac{7xyz}{(x+y)(y+z)(x+z)}}$

linear-algebra inequality contest-math intuition a.m.-g.m.-inequality

modified 4 hours ago Yuri Negometyanov 21.1k

0

votes

0

answers

5

views

Concentration of eigen values of $A^TA$ where A has the i.i.d entries from $\mathcal{N}(0,1/M)$

random-matrices

asked 4 hours ago ketan bapat 5

3

votes

1

answer

90

views

+100

How to approximate a sharply peaked function with deltas?

integration asymptotics distribution-theory approximation-theory

modified 4 hours ago A rural reader 1,339

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