Mathematics Stack Exchange

0

votes

1

answer

19

views

Application of Inclusion-Exclusion Principle to determine number of ways to choose yogurt containers

combinatorics inclusion-exclusion

answered 1 min ago Anonymous 121

1

vote

0

answers

30

views

What's the deal with recreational mathematics?

recreational-mathematics

modified 2 mins ago leonbloy 48.1k

0

votes

0

answers

4

views

Proof of Integral Test - Question on existence of convergent series to start proof - Spivak Ch.22

real-analysis calculus sequences-and-series proof-explanation solution-verification

asked 3 mins ago dc3rd 4,867

0

votes

0

answers

3

views

Extracting a cofinal subset from a directed set admitting a net whose limit superior is infinite

limits limsup-and-liminf nets

asked 3 mins ago Navukido20 13

0

votes

0

answers

3

views

The steps to calculate the derivative

matrix-calculus

4 mins ago 7337dtd 1

0

votes

0

answers

6

views

What is the probability of extracting a fixed number x from a pool of n different numbers given k trials?

combinatorics statistics binomial-distribution

modified 4 mins ago Lebowski Lebowski 1

0

votes

0

answers

17

views

Show that $g$ is continuous by using the sequence definition of continuity.

real-analysis sequences-and-series limits continuity

modified 5 mins ago Moe 71

0

votes

1

answer

8

views

Is $f(x)=\frac{\cos x}{\sqrt{x+1}}$ $\space$, $x\in(0,+\infty)$ Lebesgue integrable???

measure-theory lebesgue-integral lebesgue-measure

answered 1 min ago Alex Ortiz 14.5k

0

votes

1

answer

25

views

Finding the value of $\arctan(\frac32) - \arctan(\frac23) + \arctan(\frac25) + \arctan(\frac{1}{99})$

trigonometry

answered 6 mins ago J.G. 84.5k

0

votes

0

answers

13

views

Can a classical computer count beyond a finite number?

algorithms

asked 6 mins ago Alcatrone 11

0

votes

2

answers

29

views

Correct answer, wrong method in improper integral problem.

calculus integration improper-integrals

answered 6 mins ago heropup 85.4k

0

votes

1

answer

7

views

Exponential Growth/Rate of Change of a Microbe Colony

answered 7 mins ago Doug M 52.6k

0

votes

0

answers

7

views

Construct a sequence of step function $f_k$ so that $f_k \rightarrow f$ a.e.

analysis lebesgue-integral step-function

asked 8 mins ago Dada 311

0

votes

0

answers

3

views

Showing step functions with rational endpoints are $L^p$-dense

real-analysis measure-theory lp-spaces

asked 8 mins ago mxnoqwerty 350

0

votes

2

answers

18

views

Finding formulas for a recursive function from $\Bbb{N} \times \Bbb{N}$ to $\Bbb{N}$

discrete-mathematics elementary-set-theory recursion

answered 9 mins ago gandalf61 13.5k

0

votes

1

answer

20

views

$\frac{1}{n!}$ Normalized sum of exponentially distributed random variable converges to $\exp(1)$

probability-theory convergence-divergence

modified 9 mins ago tommik 7,368

0

votes

0

answers

13

views

How can one solve $e^{x}=\left(2x\right)^{2+x}$?

logarithms systems-of-equations

asked 10 mins ago Camishere 45 1

0

votes

1

answer

14

views

How do I solve this second order nonlinear ODE?

ordinary-differential-equations

modified 12 mins ago Aryadeva 26.4k

0

votes

0

answers

4

views

Splitting several kinds of identical objects amongst a number of non-empty groups

combinatorics permutations binomial-coefficients

asked 14 mins ago gust9999 23

0

votes

0

answers

11

views

Solve the system of equations: $u = x/(x+y), v = y/(x+y)$.

linear-algebra

modified 15 mins ago Shaun 25.1k

1

vote

0

answers

19

views

In a $T_0$ space the union of two scattered sets is scattered

general-topology

modified 15 mins ago PatrickR 1,669

0

votes

0

answers

12

views

Prove that $|x_{n+1} - x_n| \le \theta |x_n - x_{n-1}|$ for some $0 < \theta < 1$

sequences-and-series convergence-divergence

asked 16 mins ago Francisco José Letterio 1,470

0

votes

0

answers

9

views

Determine $d(A)$, when $A = \{f_n:[0,1] \to \Bbb R \vert f_n(x) = x^n, n \in \Bbb N \}$.

general-topology functional-analysis metric-spaces

asked 18 mins ago Nate 1,143

0

votes

0

answers

3

views

Applying the divergence theorem to find a trapping region

dynamical-systems divergence-theorem

asked 23 mins ago Carlo Schiano di Cola 3

0

votes

1

answer

9

views

Question regarding the properties of multiplication vectors

linear-algebra matrices vectors

answered 27 mins ago Romain Gicquaud 191

0

votes

0

answers

8

views

Bound for the number of roots of an equation

roots

asked 28 mins ago Quadratic Reciprocity 23

0

votes

0

answers

6

views

Arbitrage and Replicating a derivative

finance

asked 29 mins ago FatFeynman 235

12

votes

1

answer

374

views

+250

Function of two sets

real-analysis optimization lebesgue-measure

answered 32 mins ago user2432923 97

1

vote

0

answers

16

views

Example of $\mu_1,\mu_2$ where $\mu_{1}(F)=\mu_{2}(F)\, \forall F \in \mathcal{F}$ but $\mu_1\ne \mu_2$

real-analysis probability-theory measure-theory examples-counterexamples

modified 35 mins ago StubbornAtom 12.1k

1

vote

0

answers

27

views

Second order homogenous recurrence with non constant coefficients

sequences-and-series recurrence-relations solution-verification hypergeometric-function

modified 35 mins ago Jpk 147

0

votes

0

answers

10

views

Balls and Bins Problem: figure out the distribution of “the number of bins exactly having k balls”

probability statistics

asked 36 mins ago JWWWW 1

0

votes

0

answers

17

views

If $A$ is positive definite, and $B$ is symmetric, when does $ABA$ have (strictly) positive diagonal elements?

linear-algebra spectral-theory positive-definite symmetric-matrices

modified 38 mins ago Ruy 1,216

12

votes

0

answers

394

views

Increasing derivatives of recursively defined polynomials

real-analysis polynomials recurrence-relations roots

modified 39 mins ago Integrand 7,024

0

votes

0

answers

3

views

Assign vectors binary encodings based on dot product

linear-algebra discrete-mathematics computer-science

asked 39 mins ago PDPDPDPD 101

0

votes

0

answers

5

views

Integral depending of parameter

real-analysis

asked 41 mins ago sd19 1

0

votes

0

answers

3

views

Stochastic Integral Computation

brownian-motion martingales stochastic-integrals

asked 41 mins ago Federico Vega 33

0

votes

0

answers

38

views

Why is $\{X \in A\} = \{\omega \in \Omega \mid X(\omega) \in A\}$ a sensible shorthand?

probability-theory notation random-variables intuition

modified 41 mins ago StubbornAtom 12.1k

0

votes

0

answers

15

views

Simplify $q=\frac{0.9\times0.1^2}{9\times10^9\times1\times10^{-6}}$

linear-algebra algebra-precalculus

asked 45 mins ago Knowledge Greedy 339

0

votes

0

answers

6

views

period of state i, d=d(i) is the gcd of integer set: Ji = {n ≥ 0 | Pn(i, i) > 0

matrices arithmetic closed-form gcd-and-lcm euclidean-algorithm

modified 46 mins ago Ben Grossmann 171k

0

votes

0

answers

6

views

How to find Green's function for 2-point BVP where none of the complementary functions satisfy a BC

ordinary-differential-equations boundary-value-problem greens-function

asked 46 mins ago zabop 457

0

votes

0

answers

7

views

Probability that two random walks on the line do not intersect.

probability random-walk

asked 49 mins ago Norbert 51.3k

0

votes

1

answer

15

views

Raw Moment and Central Moment

probability probability-distributions expected-value

modified 49 mins ago StubbornAtom 12.1k

1

vote

1

answer

26

views

For the expectation of a continuous random variable $X$, why cannot both $\int^\infty_0 xf_X \, dx$ and $\int^0_{-\infty} xf_X\,dx$ equal $\infty$?

probability-theory expected-value

modified 53 mins ago StubbornAtom 12.1k

0

votes

0

answers

11

views

what does condition number of not complete power of 10 imply?

numerical-linear-algebra condition-number

asked 54 mins ago M. Chen 384

2

votes

1

answer

97

views

Summation of rational complex function

algebra-precalculus complex-numbers summation geometric-series

modified 56 mins ago Integrand 7,024

0

votes

0

answers

26

views

Integration of two dimensional function over circle?

probability integration probability-distributions expected-value

modified 58 mins ago StubbornAtom 12.1k

0

votes

0

answers

10

views

Can I recover general vector field $\mathbf{F}(\mathbf{r})$ or topology from values along a smooth curve $V(r(t)).\mathbf{r}'(t)$?

differential-geometry manifolds curves vector-bundles vector-fields

modified 59 mins ago TribalChief 119

1

vote

1

answer

22

views

Why are finite rank operators Hilbert Schmidt??

functional-analysis hilbert-spaces

answered 1 hour ago supinf 8,864

-1

votes

1

answer

40

views

Trigonometry Challenge

trigonometry

modified 1 hour ago Miguel Fernando Macias Macias 1

0

votes

0

answers

9

views

Proof verification: wealth of a certain martingale approaches $0$ almost surely after infinite bets

probability solution-verification expected-value martingales probability-limit-theorems

asked 1 hour ago Rivers McForge 2,337

0

votes

0

answers

16

views

How many ways to select a group of $5$ from $12$ such that each dislike the person to their left and right?

combinatorics combinations

modified 1 hour ago StubbornAtom 12.1k

0

votes

0

answers

15

views

What is the probability of getting a job?

probability statistics

asked 1 hour ago Juan Trevisiol 1

1

vote

0

answers

36

views

Normalizer condition implies nilpotency.

abstract-algebra group-theory finite-groups solution-verification normal-subgroups

modified 1 hour ago Shaun 25.1k

0

votes

0

answers

4

views

2-Norm of a summation of a 2D vector

summation norm

modified 1 hour ago Sebastiano 2,706

3

votes

1

answer

47

views

Distribution of random Fourier coefficients

linear-algebra probability fourier-analysis

modified 1 hour ago Qiaochu Yuan 319k

1

vote

1

answer

30

views

Does this implication involving real numbers $a$, $b$ hold?

logic

modified 1 hour ago A. E. Rosas 702

0

votes

0

answers

14

views

Computing the Hausdorff distance between any two subsets

real-analysis metric-spaces

asked 1 hour ago ToveW91 33

3

votes

1

answer

49

views

Can I check $a^b=c$ in polynomial time?

computational-complexity

answered 1 hour ago Ingix 10.7k

1

vote

0

answers

19

views

Invertible lattices in are well behaved: IJ is invertible iff I, J are

number-theory quaternions noncommutative-algebra

modified 1 hour ago sibilant 11

2

votes

1

answer

24

views

path in word graph

combinatorics graph-theory

modified 1 hour ago Exnur 96

0

votes

0

answers

15

views

Relationship between conjugacy classes of $S_n$ and the number of partitions of $n$.

abstract-algebra

asked 1 hour ago Jordan Reed 413

0

votes

0

answers

22

views

Uniformly approximating a function and its derivative

real-analysis polynomials reference-request uniform-convergence approximation-theory

modified 1 hour ago mw19930312 153

3

votes

1

answer

37

views

Find $A$ and $b$ such that $\|Ax_i + b\| \approx 1$ for a set of points $x_i, …, x_N$.

linear-algebra optimization

answered 1 hour ago Mark L. Stone 3,430

1

vote

2

answers

11

views

What is the range of $a $ such that $\frac{\log N}{N^{3a+1/2}}\rightarrow 0$ as $N\rightarrow \infty$?

convergence-divergence

modified 1 hour ago Student 121

0

votes

1

answer

32

views

Prove that the trace of alpha is the segment $AB$

differential-geometry curves

answered 1 hour ago Ted Shifrin 84.1k

0

votes

0

answers

24

views

What's algorithm to find any logarithm base when we know logarithm value and a given number x

logarithms roots

modified 1 hour ago Tomasm21 5

0

votes

1

answer

808

views

Smallest possible dimension

linear-algebra

modified 1 hour ago Community♦ 1

1

vote

0

answers

12

views

Compex analysis applications to Fluid flow. Building sophisticated flow around exterior corner and objects with composition of conformal mappings.

complex-analysis fluid-dynamics

modified 1 hour ago shegeley 11

0

votes

0

answers

14

views

Substitution of the function in an initial value problem

calculus ordinary-differential-equations functions boundary-value-problem initial-value-problems

modified 1 hour ago Antonino Roccaforte 44

0

votes

0

answers

11

views

Sequence of radius implies that a function is harmonic

analysis partial-differential-equations harmonic-functions

asked 1 hour ago julioprofe 290

2

votes

1

answer

26

views

Salt in a container - ODE problem

ordinary-differential-equations

modified 1 hour ago Math Lover 3,513

1

vote

1

answer

30

views

inverse M matrices

linear-algebra optimization nonlinear-optimization

answered 1 hour ago Mark L. Stone 3,430

1

vote

0

answers

10

views

Quadratic form with a non-symmetric positive semi-definite matrix

linear-algebra eigenvalues-eigenvectors quadratic-forms positive-semidefinite

modified 1 hour ago dv_bn 177

0

votes

0

answers

4

views

VRP with multiple locations for the came customer?

optimization integer-programming

asked 1 hour ago Magnus M 11

0

votes

0

answers

6

views

Prove that if binary relation 𝑃 is an interval order

discrete-mathematics binary

asked 1 hour ago Dina Herkovna 45

0

votes

0

answers

10

views

Understanding proof of chain rule of conditional entropy

probability conditional-probability entropy

asked 1 hour ago Rnj 13

0

votes

0

answers

12

views

Does $f(z)=(2z-1)/z^2(z-1)^2$ has a primitivie on his domain of definition in C?

definite-integrals

modified 2 hours ago C.F.G 4,626

0

votes

0

answers

8

views

Inverse Matrice Transformation

matrices finance

asked 2 hours ago lays 21

1

vote

0

answers

24

views

$8 \otimes 8$ in $SU(3)$, dimension of the Young-tableau corresponding to the $\bar{10}$

group-theory representation-theory tensor-products direct-sum young-tableaux

modified 2 hours ago Ali Chopping 105

0

votes

1

answer

25

views

How to obtain a closed form for this multiple summation formula?

summation

modified 2 hours ago Jean Marie 48.3k

0

votes

0

answers

9

views

Writing a generating function in slightly different forms and interpreting them

combinatorics discrete-mathematics generating-functions

asked 2 hours ago user833626 1

1

vote

1

answer

77

views

Estimating the number of integers in a sequence of consecutive integers that are relatively prime to a given primorial

elementary-number-theory prime-numbers primorial

modified 2 hours ago John Omielan 31.7k

0

votes

0

answers

17

views

Well Ordering Principle proof for amount of postage

proof-explanation solution-verification well-orders

modified 2 hours ago Mohsen Shahriari 3,894

1

vote

0

answers

18

views

How many matrix do we have which multiplication of all numbers in all rows and columns are 1?

number-theory combinations

modified 2 hours ago Amir reza Riahi 213

0

votes

1

answer

36

views

algebra problem-how to solve this problem?

algebra-precalculus arithmetic problem-solving

answered 2 hours ago FruDe 1,436

0

votes

0

answers

8

views

Conditional probability logic

probability conditional-probability independence

asked 2 hours ago mazuka487 13

2

votes

2

answers

68

views

Proof of a series having infinitely many zeros in the unit disc

complex-analysis

modified 2 hours ago Oliver Diaz 10.2k

5

votes

0

answers

25

views

Problems with interesting, non-trivial analogues in finite fields

soft-question finite-fields big-list conjectures

asked 2 hours ago Descartes Before the Horse 5,551

3

votes

7

answers

92

views

Does $\lim_{x\to0} \frac{f(x)}{g(x)}=1$ imply that $\lim_{x\to0}f(x)-g(x)=0$?

calculus limits asymptotics intuition

answered 2 hours ago leonbloy 48.1k

4

votes

0

answers

14

views

Can two elliptic isometreis generate a free group?

group-theory hyperbolic-geometry free-groups

asked 2 hours ago ThePiper 307

1

vote

0

answers

14

views

Proof Rényi entropy is non-negative

entropy quantum-information

asked 2 hours ago NambuGotto 11

2

votes

0

answers

11

views

Constructing a field extension (or Galois group) from the set of split primes

galois-theory algebraic-number-theory

asked 2 hours ago Benedikt Arnarsson 186

3

votes

0

answers

34

views

Number of rays intersecting at a point inside a polygon

geometry contest-math recreational-mathematics billiards

modified 2 hours ago JCr 35

2

votes

0

answers

20

views

About a chain rule for Wronskians

real-analysis reference-request chain-rule wronskian

modified 2 hours ago Martin R 54.2k

4

votes

0

answers

36

views

Is this knotted graph knotted?

general-topology graph-theory knot-theory knot-invariants

asked 3 hours ago Akiva Weinberger 17.1k

1

vote

0

answers

7

views

average spectral norm of a random matrix

linear-algebra random-matrices spectral-norm

asked 3 hours ago user2998690 21

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