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0

votes

1

answer

14

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Implicit & Explicit QR algorithms & non-convergence

linear-algebra

modified 1 min ago JeanMarie 19.4k

0

votes

1

answer

16

views

How to use congruence and angle bisector theorem for this geometry question involving isosceles triangle?

geometry

modified 1 min ago CY Kwong 114

2

votes

1

answer

11

views

Finding foot of altitude of triangle with known vertices

complex-numbers

answered 3 mins ago CY Kwong 114

0

votes

0

answers

2

views

Question on eccentricity

conic-sections

asked 5 mins ago search 113

2

votes

0

answers

37

views

+50

On the monotony of $-\int_0^1e^y\left(\frac{\operatorname{Li}_x(1-y)-\zeta(x)}{y}\right)dy$

calculus real-analysis integration limits polylogarithm

modified 6 mins ago user243301 106

0

votes

0

answers

4

views

Is a Strict monotonic Increasing' function always strictly quasi convex and strict quasi concave; do these properties add anything in addition?

derivatives convex-analysis maxima-minima

asked 7 mins ago William Balthes 6

0

votes

1

answer

23

views

Analytic function with restricted range

complex-analysis complex-numbers analytic-functions

modified 8 mins ago S717717 6,992

0

votes

0

answers

9

views

Determining a “spaghetti boundary” 0f formal $n$-squares

combinatorics discrete-mathematics

modified 9 mins ago Marcel Van de Vel 96

0

votes

1

answer

12

views

Trigonometric identities show in relation to cosx

trigonometry cubic-equations

answered 10 mins ago Bernard 75k

0

votes

0

answers

9

views

Length of shortest path

conic-sections

asked 12 mins ago user123733 855

0

votes

3

answers

29

views

Entire functions that satisfy certain equation in $\mathbb{C}$

complex-analysis

answered 12 mins ago S717717 6,992

0

votes

0

answers

24

views

Proving Fourier transform is continuous with limited knowledge.

real-analysis complex-analysis lebesgue-integral

modified 13 mins ago john melon 181

0

votes

1

answer

5

views

Optional Sampling Theorem in Continuous Time

probability-theory stochastic-processes martingales

answered 13 mins ago saz 57.8k

0

votes

0

answers

4

views

Probability that a triangle can be solved

combinatorics geometry

asked 13 mins ago simplest_mathematics 336

0

votes

1

answer

16

views

Distance between the foci

conic-sections

modified 13 mins ago JeanMarie 19.4k

1

vote

1

answer

38

views

On a certain subset of a finite group of even order

education

modified 13 mins ago LTX 21

0

votes

0

answers

4

views

Conjugation of permutations proof

group-theory permutations cyclic-decomposition

asked 14 mins ago Math_QED 1,781

0

votes

0

answers

13

views

eccentricity of locus of hyperbola

conic-sections

modified 15 mins ago user123733 855

0

votes

0

answers

6

views

The Hyperplane $H=\left [ f =\alpha \right ]$ is closed iff $f$ is continuous

functional-analysis

asked 15 mins ago Nguyễn Đăng Khải Hoàn 26

0

votes

0

answers

6

views

Equivalence of two regular languages

automata regular-language

modified 16 mins ago Lola 175

0

votes

1

answer

13

views

Can this given set be unified?

logic computer-science artificial-intelligence unification

answered 19 mins ago Derek Elkins 4,229

1

vote

1

answer

18

views

Summation splitting

sequences-and-series summation

answered 20 mins ago Olivier Oloa 91.7k

1

vote

1

answer

16

views

Finding the Expected number of steps to absorption for a Martingale based on a simple random walk.

probability-theory stochastic-processes expectation martingales stopping-times

modified 22 mins ago saz 57.8k

0

votes

1

answer

8

views

absolute values of algebraic numbers under Galois automorphism

algebraic-number-theory

answered 22 mins ago quasi 7,046

0

votes

0

answers

3

views

A small confusion with the Leslie matrix/Population growth model

linear-algebra applications

asked 23 mins ago user3604365 1

0

votes

0

answers

5

views

For what $r$ does the Lorenz attractor exist?

dynamical-systems chaos-theory

asked 25 mins ago Quantum spaghettification 251

4

votes

1

answer

138

views

Is distance function defined on a convex set is always convex?

general-topology probability-theory measure-theory metric-spaces

modified 28 mins ago Kass 58

-1

votes

2

answers

20

views

Solving a set of equations with absolute values

linear-algebra absolute-value

modified 32 mins ago Dr. Sonnhard Graubner 31.9k

1

vote

0

answers

44

views

order of automorphism group and index of finite field extension

abstract-algebra proof-verification field-theory extension-field

modified 35 mins ago Alex Vong 190

0

votes

1

answer

17

views

Unable to prove an identity regarding a circle within a triangle.

algebra-precalculus geometry trigonometry circle triangle

answered 38 mins ago G Cab 6,069

1

vote

1

answer

19

views

Continuous complex series

complex-analysis

answered 38 mins ago mrf 34k

0

votes

1

answer

5

views

Question about the coincidence between osculating plane and the tangent one.

differential-geometry surfaces curves

answered 47 mins ago Thomas 2,443

0

votes

1

answer

19

views

Normal basis for some cubic polynomials over $\mathbb{Q}$

polynomials galois-theory

modified 51 mins ago NevD 141

0

votes

1

answer

29

views

How to (dis)prove “If $f(x+n)$, where $n>0$, then graph of $f(x)$ will move to the left by $n$ units”?

functions

answered 51 mins ago law-of-fives 333

2

votes

1

answer

562

views

Finding degree and basis for a field extension

abstract-algebra extension-field

modified 1 hour ago Community♦ 1

1

vote

1

answer

55

views

what do 3D objects look like in 4D?

geometry

modified 1 hour ago lesath82 178

0

votes

0

answers

16

views

A line moves so that the sum of the perpendicular drawn to it from

analytic-geometry circle

modified 1 hour ago quasi 7,046

1

vote

1

answer

24

views

Algebraic group: Property of $f\in K[G]$.

algebraic-geometry algebraic-groups

modified 1 hour ago alggeo 51

-1

votes

0

answers

21

views

How many four-letter strings can be formed from the letters A, B, C, D, E, without allowing repetitions, that contain the letters D and E?

combinatorics discrete-mathematics

modified 1 hour ago N. F. Taussig 21.1k

2

votes

1

answer

26

views

Number of way to put $N$ dinstinct balls into $K$ distinct boxes so that a predetermined number of boxes has exactly one ball each

combinatorics

answered 1 hour ago Unknown Guy 28

3

votes

0

answers

41

views

Rotating sets apart in a regular n-gon

combinatorics discrete-mathematics cyclotomic-polynomials

modified 1 hour ago Marcel Van de Vel 96

7

votes

3

answers

208

views

+300

Smoothstep sigmoid-like function: Can anyone prove this relation?

calculus binomial-coefficients binomial-theorem

modified 1 hour ago Markus Scheuer 39.4k

1

vote

0

answers

9

views

Jointy normal correlated random variables

random-variables normal-distribution correlation

asked 1 hour ago RandomGuy 560

6

votes

1

answer

64

views

Fundamental theorem of finite abelian groups proof

abstract-algebra group-theory finite-groups

modified 1 hour ago Mathematician 42 5,445

0

votes

0

answers

6

views

Moving to a specific compass bearing using x and y coordinates while keeping velocity constant

trigonometry vectors

asked 1 hour ago Christopher James 1

0

votes

0

answers

23

views

Where did I go wrong in counting this nested loop?

algorithms

asked 1 hour ago Larssend 101

1

vote

1

answer

34

views

Dilworth's Theorem and Mirsky's Theorem for Infinite Posets?

combinatorics set-theory order-theory cardinals

modified 1 hour ago bof 34.9k

0

votes

1

answer

6

views

non linear Expectancy with binomial distribution

probability expectation

answered 1 hour ago Lazy Lee 1,003

0

votes

0

answers

3

views

Are strict Pseudo Convexity and strict Pseudo Concavity Incompatible constraints

functional-analysis continuity uniform-convergence pseudo-differential-opera

asked 1 hour ago William Balthes 6

0

votes

0

answers

7

views

If X and Y follow Geometric Distribution, which distribution will X-Y follow?

probability-distributions

asked 1 hour ago Rajat Rautela 1

-1

votes

0

answers

13

views

Is there a line integral where work is zero everywhere? (Vector field is (y,x))

calculus

modified 1 hour ago IvanT 1

0

votes

0

answers

29

views

Is there a closed form for this infinite sum?

sequences-and-series closed-form

modified 1 hour ago Wolfgang 498

1

vote

1

answer

22

views

Hermitian matrices in an arbitrary inner product

linear-algebra inner-product-space adjoint

modified 1 hour ago Ofek Gillon 1,212

2

votes

3

answers

46

views

Minimal polynomials of real algebraic multiples of roots of unity.

galois-theory extension-field roots-of-unity minimal-polynomials

answered 1 hour ago ancientmathematician 1,763

0

votes

0

answers

31

views

Generalizing a coin flipping experiment

probability dice

modified 1 hour ago Smylic 3,016

0

votes

0

answers

19

views

Some questions on the relationship between injectivity and monotone increasing functions.

functional-analysis functions continuity monotone-functions discontinuous-functions

modified 1 hour ago William Balthes 6

0

votes

1

answer

17

views

Finding out value of k1 in a cubic polynomial

linear-algebra

answered 1 hour ago Lord Shark the Unknown 4,544

0

votes

1

answer

705

views

Vapnik-Chervonenkis theory: growth function

machine-learning

modified 2 hours ago Community♦ 1

2

votes

0

answers

9

views

Why giant component of $G_{n,m}$ is Uniform along connected graphs?

probability combinatorics graph-theory random-graphs

modified 2 hours ago Romain 15

1

vote

0

answers

35

views

+50

Implicit function theorem and systems of equations

calculus real-analysis implicit-function-theorem

modified 2 hours ago Ofek Gillon 1,212

0

votes

0

answers

13

views

Path Through Invertible Elements

functional-analysis banach-algebras

asked 2 hours ago user8321044 1

1

vote

0

answers

19

views

complex differential geometry

complex-geometry several-complex-variables

asked 2 hours ago user139383 18

1

vote

0

answers

24

views

Significance of multiplication operators in operator theory

functional-analysis soft-question operator-theory

modified 2 hours ago user84647 291

1

vote

0

answers

28

views

Bezout's theorem for symmetric polynomials

real-analysis abstract-algebra complex-analysis number-theory

modified 2 hours ago Mayank M. 394

1

vote

1

answer

11

views

$N_1$ and $N_2$ are noetherian $R$-modules. Does it imply that $N_1+N_2$ is noetheran?

proof-verification modules noetherian

answered 2 hours ago Lord Shark the Unknown 4,544

8

votes

1

answer

60

views

Is it true that $1 - \prod\limits_{n=1}^{+\infty} (1-p_n(x)) \sim x$ for $x \to 0$?

calculus real-analysis sequences-and-series limits products

modified 2 hours ago Rigel 106

1

vote

1

answer

27

views

Quotient group is complete, so is the group

topological-groups

answered 2 hours ago Alex Ravsky 23.5k

0

votes

2

answers

42

views

Solve the differential equation $x\frac{dy}{dx} + y = x^3y^6$?

differential-equations derivatives

modified 2 hours ago infinitylord 1,081

2

votes

1

answer

24

views

Closed Form for an Alternating Sum Involving Binomial Coefficients

combinatorics discrete-mathematics binomial-coefficients

modified 2 hours ago Yikai 7,628

0

votes

0

answers

17

views

finding expected value with binomial distribution

probability expectation

asked 2 hours ago dvd280 39

0

votes

0

answers

21

views

Does this isomorphism preserve the norm?

functional-analysis c-star-algebras

asked 2 hours ago user8321044 1

-1

votes

0

answers

9

views

Vector and vector fields on a manifold

differential-geometry

asked 2 hours ago shinobi20 41

1

vote

0

answers

18

views

How to prove that there is at least 1 triangle of same colour?

pigeonhole-principle

modified 2 hours ago mlc 2,570

1

vote

0

answers

22

views

How many different uses of the word “model” are there in mathematics?

geometry reference-request terminology definition model-theory

asked 2 hours ago Chill2Macht 10.8k

1

vote

1

answer

29

views

Integral of exponential quadratic and linear

linear-algebra integration definite-integrals exponential-function

modified 2 hours ago Andreas 2,487

0

votes

0

answers

11

views

Existence of a (m+1)-dimensional cylinder inside a (m+1) open ball

general-topology analysis differential-equations

asked 2 hours ago Gianmarco Vidotto 21

1

vote

0

answers

22

views

Slope of a line which is both tangent and normal to a given curve

algebra-precalculus

asked 2 hours ago navinstudent 466

0

votes

0

answers

6

views

Continuity and differentiability of cumulative distribution function

continuity

asked 2 hours ago onelessproblem 74

0

votes

0

answers

6

views

Any connected planar trivalent graph has at least a face of at most degree 5

combinatorics graph-theory planar-graph

asked 3 hours ago Jo Be 317

0

votes

0

answers

12

views

Second Derivative of u with respect to x for Canonical Form of PDE

pde

asked 3 hours ago Christopher Brent Lilly 1

0

votes

0

answers

20

views

Expected time to see pattern in stream

probability

asked 3 hours ago Zizheng Tai 140

0

votes

0

answers

7

views

(Conditional) uniform asymptotic inference

probability-theory statistics statistical-inference

asked 3 hours ago Robert W. 136

8

votes

3

answers

197

views

Prove the inequality $\frac{k(k+1)}{2}\left(\frac{a_1^2}{k} + \frac{a_2^2}{k-1} + \ldots + \frac{a_k^2}{1}\right) \geq (a_1 + a_2 + \ldots + a_k)^2$

linear-algebra inequality

modified 3 hours ago Martin Sleziak 39.8k

0

votes

0

answers

11

views

$n$th order difference equation and relation to first order difference equations

probability probability-theory recurrence-relations systems-of-equations dynamical-systems

asked 3 hours ago user63841219 49

1

vote

4

answers

37

views

If $ab$ is a square number and $\gcd(a,b) = 1$, then $a$ and $b$ are square numbers.

elementary-number-theory greatest-common-divisor square-numbers

answered 3 hours ago Ashwin Ganesan 2,955

1

vote

3

answers

25

views

Find the radius of convergence of $\sum_{n=1}^{\infty} \left(\frac{5^{n} + (-1)^{n}}{n^{3}}\right)(x-2)^{n}$

calculus convergence power-series

modified 3 hours ago Ramil 871

0

votes

1

answer

28

views

A (New?) Bilateral Babylonian Method for Calculating Square Roots

algebra-precalculus limits special-functions semigroups

modified 3 hours ago law-of-fives 333

1

vote

0

answers

10

views

How to Compute Projective Closure in General?

algebraic-geometry

asked 4 hours ago Alfred Yerger 5,458

7

votes

1

answer

36

views

Find $m\in\mathbb N$, $n\in\mathbb N$, and $f(0)$ where $f(x)=ax^3+bx^2+cx+d$ $(a,b,c,d\in\mathbb Z)$, $f(mn)=1$, $f(m)=n^2$, $f(n)=m^2$, …

algebra-precalculus elementary-number-theory

modified 4 hours ago Micah 23.7k

2

votes

0

answers

14

views

Amenable groups and action

group-theory group-actions amenability

asked 4 hours ago Max 66

0

votes

1

answer

15

views

Adjunction space and composition

general-topology quotient-spaces

answered 4 hours ago Peter Elias 103

1

vote

0

answers

15

views

Given a presentation of a group, find its normalizer

group-theory free-groups

asked 4 hours ago Yuliya 6

0

votes

0

answers

13

views

Number of selections with replacement to choose every object at least $n$ times

probability coupon-collector

modified 4 hours ago Koz Ross 177

0

votes

1

answer

23

views

Prove A function $f:\mathbb{R^{2}}\rightarrow\mathbb{R^{2}}$ is continuous if the inverse image of every open set is open.

general-topology

answered 4 hours ago Henno Brandsma 55.9k

4

votes

3

answers

123

views

+50

Proof that $\sum\limits_{j,k=1}^N\frac{a_ja_k}{j+k}\ge0$

sequences-and-series inequality

answered 5 hours ago Jacob Claassen 88

5

votes

0

answers

29

views

Perturbation property of Orthonormal basis for Hilbert space

functional-analysis hilbert-spaces

modified 6 hours ago Michael Hardy 171k

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