Mathematics Stack Exchange

-1

votes

0

answers

3

views

Group theory - quotient groups

group-theory permutations

asked 2 mins ago winterdeur 4

1

vote

1

answer

9

views

Permutation and Combiantion(Selection with condition)

combinatorics

answered 2 mins ago Dbchatto67 2,629

0

votes

0

answers

25

views

Who gets the broccoli stick? Random walk in a circle.

probability statistics conditional-probability random-walk

modified 3 mins ago leonbloy 42.2k

0

votes

0

answers

2

views

Residue at a pole of order 1

complex-analysis proof-verification

asked 3 mins ago user398843 703

0

votes

0

answers

3

views

Real Numbers Proof

proof-writing proof-explanation real-numbers

asked 4 mins ago Stanley Hudson 2

0

votes

1

answer

9

views

Solving Wave Equation on $0 < x < L$ with initial condition containing both sine and cosine terms

pde boundary-value-problem wave-equation

answered 5 mins ago Dylan 14.2k

0

votes

0

answers

7

views

Alternatives to Graham-Schmidt

real-analysis functional-analysis normed-spaces

modified 5 mins ago Zduff 1,740

0

votes

0

answers

15

views

Prüfer Groups and Product Topologies

algebraic-number-theory abelian-groups topological-groups locally-compact-groups adeles

modified 7 mins ago Wayne 304

0

votes

0

answers

5

views

If $\pi(x,y)=x$ and $F$ is closed, $\pi(F)$ is closed..

analysis

asked 8 mins ago Matheus Nunes 65

5

votes

2

answers

83

views

What will be $\lim\limits_{x \rightarrow 0^+} \left ( 2 \sin \left ( \frac 1 x \right ) + \sqrt x \sin \left ( \frac 1 x \right ) \right )^x$?

calculus limits

modified 12 mins ago farruhota 21.8k

2

votes

1

answer

25

views

Showing that $f \in R_\alpha[a,b]$ and $\lim_{n\rightarrow \infty}\int_a^b f d\alpha_n = \int_a^b f d\alpha $

integration riemann-integration stieltjes-integral

modified 16 mins ago RRL 53.5k

0

votes

0

answers

6

views

Help formulating a conjecture about the parity of every cycle length in a bipartite graph and proving it

graph-theory induction formal-proofs bipartite-graph

asked 18 mins ago neet 16

0

votes

1

answer

20

views

Fit data to function $g(t) = \frac{100}{1+\alpha e^{-\beta t}}$ by using least squares method (projection/orthogonal families of polynomials)

linear-algebra numerical-methods numerical-linear-algebra

answered 20 mins ago farruhota 21.8k

-1

votes

0

answers

6

views

Perspective in computer graphics

vectors

asked 21 mins ago LanaDR 160

0

votes

1

answer

21

views

Proof of integration by substitution directly from the definition of Riemann integral.

calculus integration definite-integrals substitution

modified 21 mins ago RRL 53.5k

2

votes

2

answers

19

views

$f:\Bbb{R} \rightarrow \Bbb{R}$ uniformly continuous function such that the sequence $(f(n))$ is increasing .

real-analysis functions monotone-functions

answered 27 mins ago Robert Israel 330k

0

votes

0

answers

14

views

Is this formula correct or best practice?

circles

asked 28 mins ago zedodia 1

0

votes

0

answers

18

views

The Crank - Nicolson scheme

pde numerical-methods hyperbolic-equations

modified 29 mins ago Bhim 1

0

votes

1

answer

14

views

Do the column spaces of A^T & rref(A^T) always share the same basis?

linear-algebra matrices vector-spaces

modified 32 mins ago L KM 602

0

votes

1

answer

7

views

Triangulation without knowing the three points

triangulation

answered 34 mins ago Ross Millikan 301k

0

votes

1

answer

10

views

Derivative of a curve in a Lie group

lie-groups lie-algebras

modified 34 mins ago W. mu 755

0

votes

0

answers

4

views

Question about forward-time central-space scheme

pde numerical-methods hyperbolic-equations

modified 35 mins ago Nancy 1

0

votes

0

answers

21

views

Sheldon Axler 4.11: How to understand the proof

linear-algebra vector-space-isomorphism

asked 39 mins ago Jack Zhou 8

1

vote

1

answer

9

views

Show that $\sum_{n=2}^{\infty}\frac{(-1)^{n}}{lnn}(1+tan\frac{1}{n})^{2019}$ converges.

real-analysis convergence

answered 41 mins ago Robert Israel 330k

0

votes

0

answers

5

views

What curve represents random sampling sorted by frequency?

sampling

modified 43 mins ago David G. Stork 12k

0

votes

1

answer

15

views

getting negative variance, can't figure out what I'm doing wrong

statistics

answered 45 mins ago Robert Israel 330k

1

vote

0

answers

25

views

What physical features of the tetrahedron prevent its symmetry group from being all of $S_4$?

group-theory geometry symmetric-groups polyhedra

modified 46 mins ago hengxin 1,627

0

votes

0

answers

9

views

A “counterexample” on Takens' embedding theorem for phase space contruction

ordinary-differential-equations dynamical-systems time-series chaos-theory

modified 48 mins ago Z Wang 71

1

vote

1

answer

27

views

How to show $Z_2[x]/(x^3+x+1)$ is not isomorphic to $Z_2[x]/(x^3+x^2+1)$

abstract-algebra ring-theory

answered 49 mins ago M. A. SARKAR 2,491

1

vote

0

answers

22

views

How do we obtain an estimate for $\textbf{P}(X\geq 1)$ where $X\sim\text{Exp}(\lambda)$?

statistics exponential-distribution

modified 55 mins ago user1337 477

0

votes

0

answers

5

views

Does there exist a diffeomorphism satisfying this condtion?

real-analysis analysis jacobian diffeomorphism

modified 55 mins ago Rubertos 5,781

1

vote

1

answer

29

views

Limit Comparison Test with upside-down division

sequences-and-series convergence limits-without-lhopital divergent-series

answered 56 mins ago L KM 602

0

votes

0

answers

12

views

An open cover $([0,1] \cap \Bbb{Q}) \times ([0,1] / \Bbb{Q})$ has no finite subcover?

general-topology analysis

modified 57 mins ago BAYMAX 2,998

0

votes

0

answers

9

views

$u=f􏰀(\frac{x}{y})$ as a solution to $\Delta u = 0$

ordinary-differential-equations pde laplacian

asked 57 mins ago meff11 56

1

vote

1

answer

9

views

pebble game take up to $\lfloor\frac{k-1}{2}\rfloor$ from $k$ pebbles left

algorithms

answered 1 hour ago Ross Millikan 301k

0

votes

0

answers

10

views

When is the rank of this matrix equal to 1?

matrices

asked 1 hour ago Vasting 177

1

vote

1

answer

47

views

Proof that Good Kernels are Approximations of Identity in $L^p(\mathbb R^d)$

real-analysis proof-verification lebesgue-integral lp-spaces convolution

modified 1 hour ago Gaby Alfonso 1,198

1

vote

1

answer

13

views

If $c_{n}=\frac{n\cos(n\pi)}{n+1}$, find $\limsup c_{n}$ and $\liminf c_{n}$.

real-analysis sequences-and-series proof-verification limsup-and-liminf

modified 1 hour ago Eevee Trainer 10.1k

0

votes

1

answer

20

views

Eventually bounded sequence is bounded vice-versa

real-analysis sequences-and-series

answered 1 hour ago L KM 602

0

votes

0

answers

4

views

For an integral extension $A \subseteq B$, $\sqrt{IB}\cap A=\sqrt{I}$

commutative-algebra modules integral-extensions

asked 1 hour ago Andrew 378

0

votes

2

answers

10

views

confidence interval calculation and z score

statistics confidence-interval

answered 1 hour ago farruhota 21.8k

0

votes

0

answers

7

views

Volume of a tent with canvas stretched from a circular base to a vertical semicircular rod

calculus volume

asked 1 hour ago Jordan 18

-1

votes

0

answers

5

views

having variable as linear factor and exponent,

exponential-function

asked 1 hour ago Stephan Ketterer 1

0

votes

0

answers

20

views

Let $A\in\mathbb{R}^{m\times n}$, and $Ax=b$ has a solution for each vector $b$, prove that

linear-algebra matrices linear-transformations symmetric-matrices

modified 1 hour ago dantopa 6,664

0

votes

0

answers

3

views

Master Theorem for Algorithms - Clarifying the general recurrence $T(n) = aT(\frac{n}{b})+f(n)$ when $f(n) \in \theta(n)$

algorithms recurrence-relations

asked 1 hour ago WhatToDisplay 1

0

votes

1

answer

16

views

Expectation of a random variable with function

statistics random-variables expected-value

answered 1 hour ago heropup 65.4k

0

votes

0

answers

6

views

Changing basis in the tangent space to a sphere between homogeneous space skew symmetric matrix and stereo-graphic projection

differential-geometry manifolds homogeneous-spaces

asked 1 hour ago N Dizzle 62

1

vote

0

answers

29

views

General Properties of Limits, Problems in understanding

calculus

modified 1 hour ago Arturo Magidin 266k

0

votes

0

answers

16

views

Locus of a point without using any equation.

locus

asked 1 hour ago Divya Prakash Sinha 41

0

votes

1

answer

20

views

Is the following sequence $x_{n}=\frac{1 +(-1)^n}{n}$ Cauchy?

real-analysis cauchy-sequences

answered 1 hour ago rolandcyp 2,319

0

votes

1

answer

24

views

How to prove Φ(T) is an isomorphism

linear-algebra linear-transformations

modified 1 hour ago Unit 5,055

0

votes

0

answers

4

views

How to show $x-y^2+z^2=0$ and $y^2+z^2<4$ is a smooth manifold?

manifolds smooth-manifolds

asked 1 hour ago hoya2021 38

2

votes

1

answer

16

views

$f : M → M$ be a transitive continuous transformation, if $\phi \circ f=\phi$, then $\phi$ is constant.

proof-verification continuity metric-spaces

answered 1 hour ago Tsemo Aristide 60.3k

1

vote

0

answers

21

views

Solving for $t$ in $A \sec^2(t) + (1-A)\sec^2(at) = B$

algebra-precalculus trigonometry

modified 1 hour ago Blue 49.5k

0

votes

1

answer

19

views

Ring of Integers of Number Field

number-theory algebraic-number-theory

modified 1 hour ago Arturo Magidin 266k

0

votes

0

answers

10

views

How to get an equation system from a Simplex table

linear-programming simplex

modified 1 hour ago Brian 1,272

0

votes

1

answer

15

views

Matrix rings and finitely generated ideals.

abstract-algebra ring-theory ideals

modified 2 hours ago numericalorange 1,922

0

votes

0

answers

24

views

What is the volume above the cone $z= \sqrt{x^2+y^2}$ and bounded by the spheres $𝑥^2+y^2+𝑧^2=1$ and $𝑥^2+y^2+𝑧^2=4$?

integration multivariable-calculus definite-integrals spherical-coordinates cylindrical-coordinates

modified 2 hours ago Fiery Elements 1

0

votes

0

answers

14

views

Why algebra generated by any set $A$ is of the form $\cup_{i=1}^{m}\cap_{j=1}^{n_i} A_{ij}$?

general-topology measure-theory

asked 2 hours ago The R 65

0

votes

0

answers

8

views

Defining a custom probability density function for Maximum likelihood in matlab

statistics matlab maximum-likelihood

asked 2 hours ago sam_rox 506

0

votes

0

answers

15

views

Understanding the proof of Snell Envelope Optimal Stopping Time

stochastic-processes self-learning stopping-times

modified 2 hours ago kasa 333

0

votes

0

answers

9

views

Variation of the Christoffel Symbols

differential-geometry riemannian-geometry

asked 2 hours ago Tom 357

0

votes

0

answers

8

views

Showing log(Wt) is a martingale using Ito's Formula

stochastic-processes brownian-motion martingales

asked 2 hours ago af5432 1

0

votes

0

answers

4

views

Evolution equation of $g_{\sigma, \eta}$ in Huisken and Sinestrari's paper

riemannian-geometry mean-curvature-flows

asked 2 hours ago George 867

0

votes

0

answers

9

views

How to use the parameterization to find volume of ellipsoid?

manifolds smooth-manifolds

modified 2 hours ago hoya2021 38

0

votes

0

answers

7

views

Showing that the upper half plane has the same induced topology from (\Bbb R^2,T_st) in the quoitent and subspace toplogy.

general-topology proof-verification proof-writing quotient-spaces

asked 2 hours ago can'tcauchy 1,022

0

votes

0

answers

16

views

Comparison of partial sums of two series with positive terms.

sequences-and-series

asked 2 hours ago Alexandre Eremenko 2,465

0

votes

0

answers

17

views

confusion about Galois correspondence

abstract-algebra field-theory galois-theory

asked 2 hours ago user500144 76

1

vote

1

answer

16

views

calculate the order of the subgroup of n-th residues mod n^2

number-theory quadratic-residues

modified 2 hours ago Mohit 970

0

votes

0

answers

5

views

Stability analysis of Euler's implicit method for simple pde

pde numerical-methods stability-in-odes

modified 2 hours ago Mattos 2,831

0

votes

0

answers

22

views

Optimization Calculus - Largest rectangle that can be inscribed in an ellipse

calculus optimization

modified 2 hours ago N. F. Taussig 45.1k

0

votes

0

answers

10

views

Generalizing a formula for enumerating rooted k-ary trees from doing so with ternary trees?

combinatorics graph-theory trees groups-enumeration

asked 2 hours ago J Loredo 1

1

vote

0

answers

20

views

Prove that there is a number that appears at least N times

combinatorics pigeonhole-principle

modified 2 hours ago Arvin Ding 14

1

vote

0

answers

17

views

Can this integral be made non-positive?

differential-geometry differential-topology riemannian-geometry smooth-manifolds spherical-geometry

modified 2 hours ago Eduardo Longa 1,953

0

votes

0

answers

8

views

Algorithm for planar minimum spanning tree

planar-graph

asked 2 hours ago Rafi 5

1

vote

0

answers

9

views

Complement of tubular neighborhood

differential-geometry differential-topology smooth-manifolds geometric-topology

asked 2 hours ago Eduardo Longa 1,953

2

votes

0

answers

16

views

Inequality on the integral of the average of $f$.

real-analysis measure-theory lebesgue-integral

asked 2 hours ago Little Bird 56

1

vote

1

answer

17

views

Functional analysis: Inner Product and Haar, Rademacher, Walsh functions

real-analysis functional-analysis

answered 2 hours ago Martin Argerami 129k

0

votes

0

answers

7

views

3D Affine Rotation Matrix from Orthogonal Vectors

transformation rotations affine-geometry

asked 2 hours ago Clemson 45

1

vote

0

answers

17

views

How to show that strictly hyperbolic implies strongly well posed?

functional-analysis analysis pde hyperbolic-equations

asked 2 hours ago ImNotThereRightNow_ 103

0

votes

0

answers

12

views

Fourier Analysis an Introduction chap 3 exercise 19

fourier-analysis

asked 2 hours ago John He 47

0

votes

1

answer

40

views

Inverse Laplace Transform of $e^{-s^{\alpha}} $

integration laplace-transform inverselaplace

modified 2 hours ago Eric Towers 33.6k

0

votes

0

answers

9

views

Maximal Ideal of the Stalk generated by Linear Forms

algebraic-geometry

asked 2 hours ago KarlPeter 642

0

votes

0

answers

12

views

Prove norm on any Hilbert space is strictly convex

convex-analysis hilbert-spaces inner-product-space

asked 3 hours ago The R 65

6

votes

2

answers

561

views

Stiefel-Whitney class of complex projective spaces

algebraic-geometry differential-geometry algebraic-topology geometric-topology characteristic-classes

modified 3 hours ago Michael Albanese 64.5k

1

vote

0

answers

8

views

A weird inequality regarding integrals, limits, as well as sequence of functions.

real-analysis limits sequence-of-function

asked 3 hours ago Vladimir 6

6

votes

0

answers

86

views

+50

Is there a notion of a continuous basis of a Banach space?

functional-analysis banach-spaces distribution-theory bochner-spaces schauder-basis

modified 3 hours ago Keshav Srinivasan 2,445

1

vote

0

answers

44

views

How to solve the given Partial Differential Equation?

pde maple change-of-variable

modified 3 hours ago Ahmad 21

0

votes

0

answers

9

views

Distribution of Uniform RVs

statistics

asked 3 hours ago dsmalenb 66

2

votes

0

answers

12

views

Solutions to $\Delta u = u_{xx} + u_{yy} + u_{zz} = 0$ that only depend on r

pde harmonic-functions laplacian

asked 3 hours ago meff11 56

2

votes

1

answer

23

views

Finding Annihilators for Recurrence Relations

discrete-mathematics recurrence-relations fibonacci-numbers

answered 3 hours ago Leucippus 19.8k

0

votes

2

answers

18

views

Name for network in which nodes only have two different degrees

graph-theory reference-request network

modified 3 hours ago David G. Stork 12k

1

vote

1

answer

22

views

Ordinary differential equations - solution domain

ordinary-differential-equations

modified 4 hours ago Ertxiem 667

0

votes

1

answer

11

views

Inner Product on space of piecewise continuous functions

real-analysis functional-analysis

answered 4 hours ago Kavi Rama Murthy 72.9k

9

votes

1

answer

1k

views

A problem about the twisted cubic

algebraic-geometry commutative-algebra algebraic-curves

modified 4 hours ago Community♦ 1

0

votes

0

answers

14

views

Asymptotic Big-Omega Proof

asymptotics computer-science

asked 4 hours ago Shrek.Spongebob 34

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