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Prove $\sqrt{a} \cos^2(\theta) + \sqrt{b} \sin^2(\theta) < \sqrt{c}$ if $a\cos^2(\theta) + b \sin^2(\theta) < c$

calculus inequality convex-analysis recreational-mathematics problem-solving

modified 50 secs ago crystal_math 1,266

1

vote

0

answers

14

views

The cyclotomic polynomial analogue for $A_n$.

abstract-algebra group-theory galois-theory algebraic-number-theory symmetric-groups

modified 1 min ago ReverseFlow 752

0

votes

0

answers

2

views

Hard trigonometry problem

trigonometry

asked 1 min ago Math-Learner 41

0

votes

0

answers

3

views

Proving convergence for a two-dimensional integral that cannot be solved

convergence-divergence improper-integrals

asked 3 mins ago Zach Jacobs 1

3

votes

4

answers

66

views

Is Leibniz notation pointless? When is it not pointless?

derivatives

answered 3 mins ago zkutch 4,577

0

votes

0

answers

6

views

Inequality for positive real numbers

inequality contest-math

asked 5 mins ago Anderson Torres 31

2

votes

1

answer

20

views

Alternatives way to evaluate$ \int_0^1 x^{2n-1}\ln(1+x)dx =\frac{H_{2n}-H_n}{2n}$

definite-integrals alternative-proof harmonic-numbers

modified 6 mins ago Bernard 154k

1

vote

1

answer

37

views

Sine of sum proof

trigonometry alternative-proof

modified 6 mins ago Sebastiano 2,532

0

votes

0

answers

14

views

Definition about convergence of a sequence in $\mathbb{R}^n$

general-topology vector-analysis

modified 6 mins ago Daniel 1,309

0

votes

0

answers

3

views

Any idea to prove that $\coth (x)-(1-y) \coth [x (1-y)]<\frac{4 x}{1-x^4}$?

inequality alternative-proof

asked 7 mins ago katy98 267

-1

votes

1

answer

33

views

how can I integrate $\int_{-\infty}^{\infty} \frac{\sin x}{x}e^{ix}dx$?

integration definite-integrals

modified 8 mins ago Bellem 368

0

votes

0

answers

7

views

Is there a differentiable smooth max and min function that respects the distributive law?

derivatives optimization maxima-minima smooth-functions

modified 8 mins ago Kevin 1

0

votes

0

answers

27

views

Weyl group orbit of a dominant weight

combinatorics representation-theory lie-groups lie-algebras

modified 9 mins ago jack lingre 1

2

votes

1

answer

27

views

Representing second homology by embedded spheres

algebraic-topology differential-topology

answered 9 mins ago John Hughes 78.8k

0

votes

0

answers

9

views

Label a random variable using an i.i.d

group-theory measure-theory ergodic-theory

asked 9 mins ago Mariah 3,576

2

votes

0

answers

13

views

Group $G$ of order $24$ that is either $S_4$ or $G/Z(G)$ is $A_4$.

group-theory sylow-theory

modified 10 mins ago Shaun 24.1k

0

votes

0

answers

10

views

A Possibly Divergent Improper Integral

calculus integration definite-integrals improper-integrals

asked 13 mins ago qsazd 1

2

votes

0

answers

9

views

Is this a good intuition for the general approach to solving non-trivial differential equations?

abstract-algebra functional-analysis ordinary-differential-equations polynomials intuition

asked 13 mins ago Susp1cious 21

1

vote

2

answers

28

views

Pulling universal quantifier out of parenthesis makes nonequivalent statement?

propositional-calculus predicate-logic quantifiers

answered 14 mins ago Manx 4,874

0

votes

0

answers

6

views

Straight lines on surfaces other than $\mathbb{S}^2$ and $\mathbb{H}$

geometry differential-geometry riemannian-geometry surfaces noneuclidean-geometry

asked 14 mins ago Blue Various 433

2

votes

1

answer

58

views

Show that $\bigg(\dfrac{a+1}{b+1}\bigg)^{b+1}>\bigg(\dfrac{a}{b}\bigg)^{b}$ for $a,b>0$ and $a \not=b$.

calculus inequality recreational-mathematics

answered 16 mins ago Angelo 1,662

-2

votes

0

answers

19

views

Find the transpose of an operator in an inner product space

linear-algebra inner-product-space

modified 17 mins ago Jhoan Aldana 1

0

votes

1

answer

15

views

Compute the following integral (moments and the log normal distribution).

calculus integration probability-theory

answered 18 mins ago openspace 5,646

0

votes

0

answers

15

views

Evaluate $\frac{\int_{0}^{\infty}(1+x^2)^{-2012}dx}{\int_{0}^{\infty}(1+x^2)^{-2011}dx}$

integration solution-verification recursion reduction-formula

asked 21 mins ago Stranger Forever 1,089

0

votes

0

answers

28

views

How to best show that $f(a)$ is the greatest element of $f[A]$

order-theory

modified 27 mins ago Ale Tolcachier 1,491

0

votes

1

answer

15

views

Prove that the following estimator is unbiased.

statistics parameter-estimation

answered 28 mins ago openspace 5,646

1

vote

1

answer

33

views

Tightness of bound on true risk in the simplest optimistic case

probability statistics machine-learning

answered 29 mins ago MONODA43 468

3

votes

1

answer

4k

views

The largest product of two n-digit numbers which is palindrome

number-theory project-euler palindrome

modified 29 mins ago Vepir 9,270

1

vote

0

answers

11

views

Stuck on this definite integration problem

calculus integration definite-integrals

asked 30 mins ago yomayne 266

1

vote

1

answer

28

views

prove the angle of sum of vectors is always in the middle

geometry vectors

answered 30 mins ago Carl Schildkraut 16.6k

5

votes

1

answer

325

views

Is it possible for the number created by ordering $1$ to $n$ where $n > 1$ be a palindrome?

number-theory contest-math palindrome

modified 32 mins ago Vepir 9,270

0

votes

0

answers

10

views

How to find the imaginary part of $exp(-bR^2\,_2F_1(1,2/a;1+2/a,\dfrac{R^a}{it})-ict)$?

complex-analysis complex-numbers

modified 33 mins ago shahrukh 13

3

votes

1

answer

1k

views

Super palindromes

prime-numbers recreational-mathematics palindrome

modified 33 mins ago Vepir 9,270

-1

votes

0

answers

9

views

determine how many revolutions per second the tires made

ratio

asked 34 mins ago Naila 1

0

votes

0

answers

2

views

Explicit formula for the curvature of line passing through two given points in Poincare disk model.

hyperbolic-geometry

asked 34 mins ago user2554 291

0

votes

0

answers

18

views

Determining the areas above, below, and between two cumulative distributions

integration area cumulative-distribution-functions

modified 36 mins ago Jamie 1

0

votes

0

answers

6

views

Characterization of a cyclonic force field as “emerging from the origin at a constant rate and flowing uniformly in all directions”.

multivariable-calculus

modified 37 mins ago Mars 202

1

vote

2

answers

32

views

Prove or disprove: if $y'=y-y^2$ and $y(0)=a$ where $0<a<1$ then $a<y(x)\leq 1$ for any $x>0$

ordinary-differential-equations

modified 38 mins ago halrankard2 86

4

votes

2

answers

254

views

Squares of a number yields a palindrome?

elementary-number-theory binomial-coefficients decimal-expansion perfect-powers palindrome

modified 39 mins ago Vepir 9,270

0

votes

0

answers

21

views

How do I know that a plot of a function is correct?

algebra-precalculus graphing-functions philosophy

modified 40 mins ago J. W. Tanner 43.8k

3

votes

1

answer

317

views

Dynamic Programming problem palindrome

algorithms problem-solving recursive-algorithms dynamic-programming palindrome

modified 41 mins ago Vepir 9,270

1

vote

1

answer

20

views

Deciphering graph theory statement/notation.

graph-theory notation

modified 41 mins ago Especially Lime 30.1k

0

votes

1

answer

31

views

Show that any endomorphism of $\mathbb Q[x]$ is $E_{g}$ for some $g$, and find all automorphisms of $\mathbb Q[x]$

abstract-algebra ring-theory field-theory

answered 41 mins ago LAD 6,439

5

votes

1

answer

50

views

If $A \times B$ is a Lie group, are both $A$ and $B$ Lie groups?

abstract-algebra differential-geometry lie-groups

answered 41 mins ago Qiaochu Yuan 311k

2

votes

0

answers

278

views

Sum of two palindromes to a different base equals a third palindrome to a different base

elementary-number-theory recreational-mathematics number-systems palindrome

modified 42 mins ago Vepir 9,270

0

votes

0

answers

4

views

Dynamics of horocycle flow in modular surface connected to Riemann Hypothesis

reference-request dynamical-systems online-resources riemann-hypothesis modular-group

asked 42 mins ago geocalc33 1,143

1

vote

1

answer

22

views

We have n identical objects , and we want to distribute them to 3 different children A, B, C.

combinatorics discrete-mathematics

modified 44 mins ago N. F. Taussig 55.8k

4

votes

0

answers

293

views

Binary Palindrome

algorithms palindrome

modified 44 mins ago Vepir 9,270

0

votes

0

answers

4

views

Finding a subset of fixed size of a graphs vertex set that minimizes 'surface area'. AKA finding min cut for fixed partition size.

graph-theory

asked 44 mins ago mathew 1,372

0

votes

1

answer

29

views

How to find the Inverse Fourier Transform or g(t)?

fourier-series fourier-transform convolution

answered 45 mins ago md2perpe 14.4k

1

vote

1

answer

143

views

Palindrome Remove one Character

discrete-mathematics palindrome

modified 46 mins ago Vepir 9,270

-1

votes

0

answers

28

views

How to choose a good initial guess

numerical-methods approximation

modified 46 mins ago HD AQ 3

2

votes

0

answers

15

views

If $G$ is a finite group, $p$ is a prime such that $p\big||G|$ and $n_p$ is the number of Sylow $p$-subgroups of $G$, then $|Aut(G)|\leq |S_{n_p}|$.

group-theory symmetric-groups group-actions sylow-theory automorphism-group

modified 47 mins ago Bryan Castro 143

0

votes

0

answers

8

views

Apply Dvoretzy-Kiefer-Wolfowitz inequality to 2D problem

probability probability-theory inequality

asked 50 mins ago MONODA43 468

3

votes

1

answer

36

views

Are there always multiple scalar multiplications over non-prime fields?

linear-algebra abstract-algebra field-theory

answered 52 mins ago Qiaochu Yuan 311k

0

votes

0

answers

7

views

Is it possible to define a function that appears undefined if it is derived from a function that is defined?

calculus limits

asked 54 mins ago financial_physician 289

0

votes

0

answers

14

views

Epsilon delta proof, choosing inequality side

epsilon-delta

asked 57 mins ago eh98 1

0

votes

0

answers

13

views

Find number of relations R that are onto

combinatorics set-theory relations

asked 57 mins ago Mostfa shma 137

2

votes

1

answer

38

views

Definition of differentiation in context of abstract algebra.

calculus abstract-algebra

answered 59 mins ago Alekos Robotis 16.9k

0

votes

0

answers

16

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What is the derivative of this integral with a pdf

calculus integration

modified 1 hour ago ELLA 59

0

votes

0

answers

6

views

Basis vectors for Heisenberg AlgebraDifference between quasi-bialgebra and bialgebra?

abstract-algebra category-theory

asked 1 hour ago HaKuNa MaTaTa 5,227

0

votes

0

answers

25

views

How can I enumerate the transformation rules on lists of lists?

algorithms pattern-matching

modified 1 hour ago zooby 3,347

1

vote

1

answer

11

views

Decomposition of semisimple Lie groups (lie algebras) into direct products (direct sums) and the correspondence.

lie-groups lie-algebras

answered 1 hour ago Qiaochu Yuan 311k

0

votes

0

answers

12

views

Mixed-Marble Mayhem

combinatorics

asked 1 hour ago Alex Wang 11

1

vote

0

answers

25

views

Bolyai's parallel angle formula？

geometry surfaces hyperbolic-geometry noneuclidean-geometry

modified 1 hour ago Blue Various 433

0

votes

1

answer

13

views

Narrow equals wide topology on probability measures: reference?

measure-theory weak-convergence

answered 1 hour ago snar 6,259

1

vote

0

answers

32

views

Is it OK to refer results to Encyclopedia of Mathematics?

reference-works

asked 1 hour ago user3810316 317

1

vote

1

answer

20

views

Values such that piecewise function is differentiable everywhere

calculus limits derivatives

modified 1 hour ago mathcounterexamples.net 40.6k

1

vote

1

answer

26

views

Equation of a circle with two points and tangent to a circle

geometry circles

answered 1 hour ago GReyes 7,068

0

votes

1

answer

14

views

function of series after integral

real-analysis power-series

answered 1 hour ago openspace 5,646

1

vote

0

answers

11

views

What is the Bergman kernel for upper half-space?

several-complex-variables

asked 1 hour ago Ramin Barati 11

1

vote

1

answer

76

views

IMO 2002 Problem 1 (C1)

combinatorics induction contest-math

answered 1 hour ago Raiyan Chowdhury 81

0

votes

0

answers

9

views

When can every set in a monotone class $\mathcal{M}(\mathcal{C})$ be written as a countable monotone union or intersection of sets in $\mathcal{C}$?

measure-theory

asked 1 hour ago TheProofIsTrivium 817

3

votes

2

answers

45

views

finding bounds for $\int_0^X\lfloor x^2\rfloor \, dx$

integration ceiling-and-floor-functions upper-lower-bounds

answered 1 hour ago Oldboy 14.1k

1

vote

0

answers

40

views

Show that there exists $\theta\in(a,b)$ such that $\frac{f'(\theta)}{f(\theta)}=\frac{1}{a-\theta}+\frac{1}{b-\theta}.$

real-analysis solution-verification

asked 1 hour ago Sanket Biswas 3,037

2

votes

1

answer

10

views

Radon measure is inner regular if and only if it is semi-finite

measure-theory

answered 2 hours ago Sebastian Spindler 249

0

votes

0

answers

19

views

How can I tell if a coordinate is on a line with thickness and sqaure corners?

geometry

asked 2 hours ago ethtrhaef 1

1

vote

1

answer

7k

views

R - How to draw 2 box plots on one axis in R?

statistics programming

modified 2 hours ago Community♦ 1

1

vote

0

answers

28

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Proving that integral is larger than Wasserstein metric

probability-theory measure-theory inequality optimal-transport

modified 2 hours ago Davi Barreira 1,056

1

vote

0

answers

7

views

Convex surfaces in semi-Riemannian manifolds?

semi-riemannian-geometry

asked 2 hours ago Faster Dam 43

0

votes

0

answers

10

views

How to identify the upper and lower surfaces while calculating the volume bound by two given planes?

calculus definite-integrals 3d volume multiple-integral

modified 2 hours ago Integrand 6,504

0

votes

0

answers

17

views

Definition of continuity of a function of several variables in terms of topology

real-analysis continuity topological-vector-spaces

asked 2 hours ago Physer 1

2

votes

0

answers

28

views

Prove almost sure convergence for log series

probability-theory convergence-divergence probability-limit-theorems

modified 2 hours ago StubbornAtom 11.9k

1

vote

1

answer

34

views

Can somebody help me with the beginning of Laplace transform?

calculus ordinary-differential-equations laplace-transform inverse-laplace laplace-method

modified 2 hours ago Aryadeva 25.1k

2

votes

0

answers

27

views

example of a simple Galois extension over $\mathbb{Q}$

abstract-algebra galois-theory extension-field galois-extensions

modified 2 hours ago JCAA 7,569

0

votes

0

answers

7

views

Equation of a hyperbolic slot

linear-algebra

asked 2 hours ago Sabri 1

0

votes

0

answers

6

views

Maximum likelihood estimation for beta distribution

optimization maximum-likelihood hessian-matrix

asked 2 hours ago Emin Ozkan 125

2

votes

0

answers

16

views

Conservation law for the Camssa-Holm equation

partial-differential-equations

asked 2 hours ago Neldrock 145

0

votes

3

answers

62

views

Power of permutation

abstract-algebra

answered 2 hours ago Rene Schoof 371

1

vote

2

answers

507

views

Finding the interior angles of an irregular polygon inscribed on a circle

geometry trigonometry

modified 2 hours ago Peter 1

6

votes

0

answers

252

views

Square-integrability in lemma 4.30 of Folland's “A Course in Abstract Harmonic Analysis”

measure-theory proof-explanation lp-spaces harmonic-analysis

modified 2 hours ago julian 1,614

0

votes

0

answers

11

views

Mass of single point appearing in limit of spectral measure integral

measure-theory spectral-theory quantum-mechanics

asked 2 hours ago Tuneer Chakraborty 111

0

votes

1

answer

27

views

Prove that $D$ is dense in $M$

real-analysis general-topology analysis metric-spaces

answered 3 hours ago Henno Brandsma 174k

5

votes

1

answer

44

views

Let $f:\mathbb{R}\to\mathbb{R}$ be a continuous function that satisfies $f(q+1/n)=f(q)$ for every $q\in\mathbb{Q}$ and for every $n\in\mathbb{N}$.

real-analysis sequences-and-series solution-verification

modified 3 hours ago Brian M. Scott 517k

5

votes

0

answers

100

views

Almost $\pi$: a closed form expression for $\int_0^\infty \left[ \left(1+\frac 1{x!}\right)^x-1\right] dx$

sequences-and-series definite-integrals closed-form

modified 3 hours ago giobrach 5,322

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