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0

votes

1

answer

28

views

Why is $D =d/dx$ an unbounded linear operator?

linear-algebra functional-analysis

modified 1 min ago Rundasice 190

1

vote

1

answer

50

views

Analytic expression for a definite integral containing a trigonometric function and a power of x

calculus definite-integrals special-functions

modified 3 mins ago Claude Leibovici 196k

-1

votes

0

answers

2

views

Can anyone help me to find the steady state of the dicrete model?

mathematical-modeling

modified 4 mins ago Partho Sutra Dhor 1

0

votes

0

answers

2

views

Under what condition restricted m-strongly convex function is convex?

convex-analysis convex-geometry

asked 5 mins ago Sepide 928

0

votes

0

answers

7

views

Inner product of polynomials defined using determinant.

linear-algebra determinant inner-products orthogonal-polynomials

asked 6 mins ago 1Teaches2Learn 727

0

votes

3

answers

28

views

Why is $|a-b|^2=|a|^2-2a\cdot b+|b|^2$

multivariable-calculus vectors

modified 7 mins ago Lex_i 1,683

0

votes

1

answer

10

views

How to solve for when this trigonometric function intersects the line $y=1$?

trigonometry problem-solving

answered 9 mins ago Jacob A 340

0

votes

1

answer

19

views

Show that if $g(\frac{1}{2})=\frac{\pi}{2}$ then $g'(\frac{1}{2})=\frac{\pi}{2}$

real-analysis

answered 13 mins ago Jacob A 340

0

votes

0

answers

9

views

Numerical integration scheme for solving the Riccati differential equation

ordinary-differential-equations numerical-methods

modified 13 mins ago The Amplitwist 220

-3

votes

0

answers

20

views

How do I use induction to show that $\binom{2n}{r}=2^n-2$, for all $n\ge5$?

induction binomial-theorem

modified 20 mins ago eloiprime 2,967

0

votes

0

answers

6

views

Logistic Distribution risk coefficent

probability limits functions conditional-probability cumulative-distribution-functions

modified 21 mins ago Thomas Andrews 156k

-1

votes

0

answers

6

views

find volume V y = 10e−x2, y = 0, x = 0, x = 1

calculus integration functional-analysis algebra-precalculus discrete-mathematics

asked 25 mins ago Rodney Eugene 1

-1

votes

1

answer

31

views

transcendentality of the number $\pi$

algebraic-number-theory analytic-number-theory pi transcendental-numbers algebraic-numbers

modified 26 mins ago MD Hossain 1

0

votes

0

answers

40

views

Why do $V_+(x_0)$ and $\mathcal{O}(1)$ represent linearly equivalent cartier divisors on $\mathbb{P}^n_k$?

algebraic-geometry schemes divisors-algebraic-geometry

modified 28 mins ago Daniel 1,213

0

votes

0

answers

6

views

Frobenius Series solution to this ODE

ordinary-differential-equations power-series frobenius-method

asked 32 mins ago newtothis 121

0

votes

1

answer

18

views

Prove that $x\in M$ is a nondegenerate critial point if, and only if, $\nabla f(x)=0$ and $\det (d\nabla f)_x\neq 0$

manifolds smooth-manifolds submanifold

answered 33 mins ago Masacroso 23.6k

0

votes

0

answers

8

views

A question to the image of semisimple ring

abstract-algebra noncommutative-algebra semi-simple-rings

asked 35 mins ago Trần Nam Sơn 465

0

votes

0

answers

11

views

A permutation approach of Lilawati Book

combinatorics permutations combinations binomial-coefficients

modified 41 mins ago user1062 323

0

votes

0

answers

4

views

A question to matrices over real quaternion division ring

linear-algebra matrices matrix-equations matrix-decomposition quaternions

asked 43 mins ago Trần Nam Sơn 465

3

votes

2

answers

2k

views

Best book to study Lie group theory

reference-request lie-groups self-learning

modified 45 mins ago Community♦ 1

1

vote

2

answers

183

views

Covering the plane with convex polygons?

geometry tiling

answered 46 mins ago RavenclawPrefect 10.4k

-1

votes

0

answers

9

views

Proof related to zero of infinite order

complex-analysis roots analytic-functions

modified 49 mins ago Eureka 99

0

votes

0

answers

9

views

Make a function from this graph

sequences-and-series functions

modified 49 mins ago sankiago 29

0

votes

0

answers

19

views

How to prove $ ( p \land q ) \land \big( ( q \land \neg r ) \lor ( p \land r ) \big) $ is logically equivalent to $ \neg ( p \to \neg q ) $.\

logic propositional-calculus

modified 51 mins ago eva 1

1

vote

0

answers

6

views

Is there any motivation for studying prime numbers that can be represented by a quadratic form?

number-theory quadratic-forms

asked 51 mins ago Isomorphism 4,989

0

votes

1

answer

20

views

Pencil of curves of degree $d$ on $\Bbb{P}^2$ has $d^2$ base points?

algebraic-geometry surfaces projective-space

answered 51 mins ago Tabes Bridges 2,839

-1

votes

0

answers

30

views

Fourier transform of 1/sinc

integration fourier-transform

modified 53 mins ago mojtaba adeli 13

-1

votes

2

answers

83

views

Answer to this probability problem: $ \frac 1 { 24 } $ or $ \frac 5 { 24 } $?

probability probability-distributions

modified 53 mins ago Leucippus 22.5k

1

vote

0

answers

7

views

Is there a known method to dissect Jessen's icosahedron and rearrange to form a cube?

geometry polyhedra solid-geometry dissection

asked 55 mins ago lemur988 11

1

vote

0

answers

14

views

Why can a proposition hold for any given integer-sized set but not for infinite set?

elementary-number-theory

modified 55 mins ago Shu Shang 11

0

votes

1

answer

26

views

How to prove an indirectly defined mapping is smooth

differential-geometry smooth-manifolds bilinear-form smooth-functions

answered 59 mins ago Jeff Rubin 349

0

votes

0

answers

7

views

Visualizing multiplication of improper fractions

arithmetic fractions

asked 1 hour ago LinguisticChiyo 1

0

votes

1

answer

34

views

Determining the defining polynomial of a parametrized variety

algebraic-geometry commutative-algebra computational-algebra

answered 1 hour ago Viktor Burghardt 31

0

votes

1

answer

35

views

How Upper Riemann Sum is well defined?

real-analysis integration measure-theory

modified 1 hour ago Siong Thye Goh 139k

1

vote

1

answer

18

views

Why does $f'(x_{(1)})=-r_{(1)}$ in conjugate gradient?

linear-algebra derivatives gradient-descent

modified 1 hour ago Kat 101

1

vote

2

answers

29

views

Proof that the determinant of a 3x3 matrix is the volume of the parallelepiped spanned by the columns?

linear-algebra vectors determinant cross-product

answered 1 hour ago Mason 1,858

0

votes

0

answers

6

views

About the definition of $A^{e}-$mudule structure of an $A$-bimudule $M$

homological-algebra noncommutative-geometry hochschild-cohomology

asked 1 hour ago José Luis Camarillo Nava 795

0

votes

0

answers

25

views

Time evolution problem

mathematical-modeling

modified 1 hour ago Lili Nájera Canela 1

0

votes

0

answers

28

views

Two Dissimilar Integrals of the Same Integrand

integration indefinite-integrals

modified 1 hour ago Prajval K 53

0

votes

1

answer

9

views

Cartesian equation of a line parallel to the X-axis in 3D

vectors 3d

answered 1 hour ago user256872 398

0

votes

2

answers

23

views

How to find the limit of $\lim_{x \to 0} \frac{x \tan^{-1} x}{1-\cos x}$

algebra-precalculus limits

answered 1 hour ago Toby Mak 14.6k

3

votes

1

answer

53

views

Fundamental group of a compact surface

surfaces fundamental-groups

modified 1 hour ago Eric Wofsey 279k

1

vote

1

answer

18

views

How to write 1 tuple as sets?

elementary-set-theory

answered 1 hour ago Gregory Nisbet 4,769

2

votes

1

answer

45

views

An interesting ratio question about square and circle

geometry

modified 1 hour ago SpoonedBread 336

0

votes

0

answers

6

views

Show the function is concave function but not strictly concave

calculus derivatives solution-verification convex-optimization

asked 1 hour ago Nick 1,221

0

votes

1

answer

48

views

Compute $\Pr(X<Y)$ with $X$ and $Y$ being two random variables

probability random-variables

modified 1 hour ago Oliver Diaz 19k

2

votes

0

answers

21

views

Why if $x,y\in\mathbb{R}^n-\{0\} $ and $||x|| + ||y|| =||x+y ||$, then exist $\lambda > 0$ s.t. $x=\lambda y$

calculus

modified 1 hour ago 311411 2,111

0

votes

0

answers

14

views

There must exist a prime between $P_n$ and (including) $|(P_n\#)/2-2^y|$ as long as $|(P_n\#)/2-2^y| > P_n$.

solution-verification prime-numbers prime-gaps

modified 1 hour ago Isaac Brenig 1,265

0

votes

2

answers

27

views

How does spanning a vector space working here?

linear-algebra vector-spaces vectors

modified 1 hour ago Mason 1,858

1

vote

1

answer

5k

views

Principal axis of a matrix

linear-algebra matrices diagonalization

modified 1 hour ago Community♦ 1

1

vote

0

answers

16

views

A simple looking yet tricky Second Order Nonlinear Differential Equation.

calculus ordinary-differential-equations derivatives

modified 1 hour ago stanisverylow 31

12

votes

3

answers

9k

views

+200

Demonstrate another way to implement the Inclusion–exclusion principle?

combinatorics inclusion-exclusion

modified 1 hour ago linear_combinatori_probabi 1,560

0

votes

1

answer

21

views

Which of the following options must be true.

matrices eigenvalues-eigenvectors nilpotence

answered 1 hour ago Welerson Jung 57

0

votes

1

answer

38

views

+50

Equivalence of Leaky Integrator and Low-Pass Filter Decision Models

stochastic-processes computational-mathematics stochastic-differential-equations biology decision-theory

answered 1 hour ago Kat 101

0

votes

0

answers

19

views

Counting the size of a sample space

probability combinatorics solution-verification

asked 1 hour ago a6623 319

0

votes

0

answers

14

views

how does the mean of a measure of independent geometric brownian motions evolve?

stochastic-calculus stochastic-analysis stochastic-differential-equations

modified 2 hours ago Zhiyu Fu 1

0

votes

2

answers

27

views

matrix calculus: derivative of $\frac{x^T r}{\sqrt{x^T Sx}}$ with respect to $x$

multivariable-calculus optimization vector-analysis matrix-calculus

modified 2 hours ago CuriousMind 1,146

1

vote

1

answer

16

views

A rational homology $\Bbb CP^2$ is a rational cohomology $\Bbb CP^2$

algebraic-topology homology-cohomology complex-geometry projective-space

modified 2 hours ago Michael Albanese 84.4k

0

votes

0

answers

28

views

Example of such a function?

real-analysis derivatives asymptotics taylor-expansion

modified 2 hours ago Maman 2,631

0

votes

0

answers

42

views

Does polynomial of degree $0$ exist?

polynomials

modified 2 hours ago Welerson Jung 57

0

votes

0

answers

8

views

“Weak Links” in a “Small World” Network

graph-theory network

asked 2 hours ago Togy Jose 1

-1

votes

0

answers

39

views

is 713,000 a square modulo 2021?

number-theory

asked 2 hours ago seb 1

0

votes

0

answers

12

views

For most prime powers $q$, an elliptic curve over $\mathbb{F}_q$ has a point of order greater than $4\sqrt{q}$

prime-numbers elliptic-curves

modified 2 hours ago Alan Wang 8,441

2

votes

0

answers

88

views

+50

Evaluation of $\mathrm{\sum\limits_{n=0}^\infty \left(C(n)-\frac12\right)+ \sum\limits_{n=0}^\infty \left(S(n)-\frac12\right)}$

calculus sequences-and-series special-functions trigonometric-series constants

modified 2 hours ago Tyma Gaidash 2,193

1

vote

0

answers

11

views

Pareto-optimal front in $m$-dimensional space can not have more than $\mathbf{H}_{m-2}$ homology groups

convex-optimization homology-cohomology topological-vector-spaces simplicial-complex

modified 2 hours ago ramgorur 373

0

votes

1

answer

17

views

If $\theta\in S_n$ is an $(n-1)$-cycle where $n\geq 3$, then $C_{S_n}(\theta)=\langle \theta \rangle$.

abstract-algebra group-theory permutations symmetric-groups

answered 2 hours ago Alan Wang 8,441

0

votes

0

answers

15

views

Exists lagrangian subspace $L$ such that $L \cap W_j = \{0\}$.

symplectic-geometry symplectic-linear-algebra

modified 2 hours ago PaulichenT 151

0

votes

1

answer

871

views

Minimal and caracteristic polynomial of a matrix 2x2.

polynomials minimal-polynomials

modified 2 hours ago Community♦ 1

1

vote

1

answer

31

views

Vector differentiation and rotating frames

calculus vector-analysis

answered 2 hours ago Rezha Adrian Tanuharja 6,901

0

votes

0

answers

10

views

Laplace transform of nonlinear differential system

laplace-transform

3 hours ago Sergio García 1

0

votes

1

answer

10

views

Gelfand-Kolmogorov-type theorem for $C_0(X)$?

functional-analysis gelfand-representation

modified 3 hours ago supergeneric 59

-1

votes

1

answer

15

views

Example of a holomorphic function on a non simply connected set which has a (global) primitive

complex-analysis

answered 3 hours ago Zhooo 399

0

votes

0

answers

9

views

Open Source Tools for Graph Analytics

visualization network

asked 3 hours ago Togy Jose 1

2

votes

1

answer

34

views

Proof of: There exists a function which dominates all computable ones

functions computer-science turing-machines

answered 3 hours ago Noah Schweber 206k

0

votes

0

answers

5

views

Finite type versus finite presentation hypothesis on extending a morphism on stalks

schemes birational-geometry

asked 3 hours ago Nico 1,124

2

votes

0

answers

26

views

Winning probability for throwing one and two balls

probability

modified 3 hours ago N. F. Taussig 60.6k

3

votes

2

answers

110

views

+150

What does it mean to sample from a hypergeometric distribution?

probability probability-distributions random-variables

modified 3 hours ago Oliver Diaz 19k

1

vote

1

answer

21

views

Prove that absolute value of function is less or equal to integral of function squared

integration

answered 3 hours ago Drizzle 23

0

votes

0

answers

31

views

Positive Definite Matrix and Rectangular Matrix

linear-algebra matrices inequality determinant positive-definite

modified 3 hours ago River Li 16.9k

0

votes

0

answers

32

views

I'm having doubts about solving a problem involving fractions.

combinatorics

asked 3 hours ago Bah Soh 63

4

votes

1

answer

32

views

Local fundamental theorem of affine geometry

convex-analysis affine-geometry simplex

modified 3 hours ago Eric Wofsey 279k

1

vote

1

answer

18

views

Is every finite, connected k-regular graph a quotient of the infinite k-regular Tree?

graph-theory covering-spaces

modified 3 hours ago Misha Lavrov 95.4k

0

votes

0

answers

7

views

Asymptotic estimate for EGF surjections

combinatorics asymptotics generating-functions

asked 3 hours ago Luis Alexandher 447

0

votes

0

answers

9

views

what is the degree of freedom when the constraint functions don't have the same variables as the target function?

calculus optimization

asked 3 hours ago rookie 309

1

vote

0

answers

14

views

Sum of a Measurable Set and Open Set

real-analysis measure-theory lebesgue-measure

asked 4 hours ago user193319 6,488

0

votes

0

answers

8

views

Control Law singularity when equilibrium is reached

control-theory singularity lyapunov-functions

asked 4 hours ago Sergio García 1

0

votes

0

answers

10

views

Mathematical logic and Geometry

euclidean-geometry propositional-calculus noneuclidean-geometry

asked 4 hours ago Ash 325

1

vote

0

answers

18

views

Alternative Proof: How to show that a theory with arbitrarily large finite models has an infinite model without compactness or ultraproducts?

model-theory alternative-proof

modified 4 hours ago Gregory Nisbet 4,769

2

votes

0

answers

23

views

A pathological example of a distribution.

derivatives distribution-theory

modified 4 hours ago Lolman 1,327

1

vote

0

answers

12

views

Eliminating weak strategy isn't order dependent

order-theory game-theory utility

modified 5 hours ago the correct answer 344

2

votes

2

answers

184

views

Proving $\binom{2n}{n} \geq \frac{2^{2n}}{n+1}$ combinatorially

combinatorics combinatorial-proofs catalan-numbers

answered 6 hours ago Mike Earnest 47.3k

16

votes

4

answers

17k

views

How do pocket calculators calculate exponents?

exponential-function exponentiation calculator

modified 6 hours ago 徐持恒 Xu Chiheng 1

2

votes

1

answer

43

views

Non-algebraic flops

algebraic-geometry birational-geometry

answered 6 hours ago hyyyyy 173

3

votes

3

answers

74

views

Proof that if $p$ divides $bc$, then $p$ divides $c$ or $p$ divides $b$

elementary-number-theory proof-writing solution-verification proof-explanation

answered 6 hours ago DanielWainfleet 49.8k

6

votes

1

answer

102

views

Do there exist integers $a_1,a_2,\ldots,a_{n-1},a_n,a_1,a_2,\ldots$ such that $a_i+a_{i+1}+a_{i+3}=1$?

linear-algebra elementary-number-theory

answered 7 hours ago jjagmath 6,058

0

votes

2

answers

52

views

What are some ways to show that $1$ is not first-order definable in $(\mathbb{R}, +, 0, \le)$?

model-theory alternative-proof

modified 7 hours ago Gregory Nisbet 4,769

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