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9

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need Help with calculus logic question

calculus proof-verification logic alternative-proof

modified 1 min ago MWillson 1

0

votes

0

answers

2

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Definition of measure on an algebra violating algebra definition

abstract-algebra measure-theory

asked 1 min ago Red Floyd 285

0

votes

0

answers

2

views

Why $f: A \to A$ being injective not implies it is also surjective when $A$ is infinite?

functions

asked 1 min ago İbrahim İpek 459

2

votes

1

answer

16

views

A question about approximations.

physics approximation

modified 2 mins ago guest 3

0

votes

1

answer

12

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I can't find the maximum value of P because of some problems in my solution.

inequality

answered 2 mins ago Michael Rozenberg 127k

0

votes

0

answers

3

views

Is interchanging the order of multiple integration valid here?

calculus multivariable-calculus mathematical-physics multiple-integral solid-angle

asked 2 mins ago Joe 269

1

vote

1

answer

16

views

Is the size of a 1 dimensional vector space over a finite field the same size as the field?

linear-algebra

answered 3 mins ago kccu 14.2k

0

votes

1

answer

16

views

Sum of quadratic residues.

number-theory modular-arithmetic

answered 4 mins ago Bernard 133k

-1

votes

1

answer

10

views

complex number substitution within a function

complex-numbers

answered 5 mins ago Allawonder 6,204

-1

votes

2

answers

9

views

Solve: The equation $7x^2-(R+13)x+R^2-R-2=0$ has one real root in range (0,1) and one real root in range (1,2). What's the range of R?

discriminant

answered 6 mins ago Dr. Sonnhard Graubner 89.2k

0

votes

0

answers

5

views

What does the functional elements of L^0,L^1 and L^infinity look like?

functional-analysis stochastic-calculus finance measurable-functions

asked 6 mins ago user419001 1

0

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0

answers

6

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Uniform continuous and Hölder on dense subset is Hölder continuous

real-analysis proof-verification

modified 7 mins ago badatmath 938

-1

votes

0

answers

22

views

Simple problem, simple answer. How to formalize?

probability-theory statistics expected-value

modified 7 mins ago Yeg0R 1

0

votes

1

answer

15

views

How to prove the following statement

real-analysis functions continuity

answered 8 mins ago almagest 12.2k

0

votes

2

answers

25

views

Difficult logic question with conditional statements

calculus proof-verification logic conditional-expectation

answered 10 mins ago Manx 412

2

votes

1

answer

4

views

Solution of least-squares problems \vert(x*s-e)\vert with Ax=b

optimization least-squares

modified 10 mins ago dmtri 1,928

1

vote

1

answer

755

views

Calculating stability and order of implicit midpoint scheme

ordinary-differential-equations numerical-methods

modified 11 mins ago Community♦ 1

0

votes

2

answers

39

views

How to prove that $(1+x)^r$ behaves like $1+rx$ for small x without calculus?

approximation-theory

modified 11 mins ago J.G. 47.5k

0

votes

1

answer

13

views

Use composition of functions to derive the function that relates oral dosage to the amount of drug that reaches the sinus cavity.

algebra-precalculus

modified 12 mins ago Andrew Chin 1,168

3

votes

1

answer

27

views

Does $\dfrac{dx}{dy}$ at $0$ exist and $\dfrac{dy}{dx}$ . $\dfrac{dx}{dy}$ at $0$ is $1$ for the following function?

real-analysis calculus derivatives

answered 12 mins ago Allawonder 6,204

0

votes

1

answer

7

views

A finite-diameter Riemannian manifold with properly embedded infinite geodesics

differential-geometry differential-topology riemannian-geometry smooth-manifolds riemannian-metric

answered 14 mins ago Travis 69.6k

2

votes

0

answers

11

views

Determine a formula where $f(1)=1$ and for $n>1$, $f(n)=(n+1)/3n\times f(n-1)$.

real-analysis

modified 14 mins ago dmtri 1,928

0

votes

1

answer

11

views

How to substitute a complex number in a complex function?

complex-numbers

answered 17 mins ago J.G. 47.5k

0

votes

0

answers

7

views

Every block is eulerian graph is eulerian

discrete-mathematics graph-theory

asked 17 mins ago Renat Sergazinov 86

0

votes

0

answers

12

views

Number of zeros in the decimal representation of $2^n$

number-theory elementary-number-theory

modified 18 mins ago Andrew Chin 1,168

0

votes

0

answers

8

views

$f:\mathbb{R}^n\to\mathbb{R}^n$ is diffeomorphism iff $f$ is local diffeomorphism and proper map

real-analysis differential-geometry differential-topology diffeomorphism

asked 19 mins ago GRJ 23

0

votes

0

answers

2

views

Supermodular independent product of generalized measures (capacities)

measure-theory

asked 20 mins ago George 1

0

votes

0

answers

5

views

Need help with mobius function

combinatorics number-theory mobius-function mobius-inversion

modified 21 mins ago NoOb 101

0

votes

1

answer

8

views

Canonical isomorphism between $H_0(X, A)$ and $A$ for $X$ a topological space.

algebraic-topology homology-cohomology

answered 21 mins ago Ayman Hourieh 32.4k

0

votes

1

answer

23

views

Limit of a sequence by epsilon delta definition

real-analysis sequences-and-series

answered 22 mins ago Khosrotash 16.9k

0

votes

1

answer

16

views

Convergence behaviour of an iteration of a square root using Halley's method.

numerical-methods recurrence-relations fixed-point-theorems

modified 26 mins ago Wesley Strik 2,460

2

votes

0

answers

10

views

Compact Support of a function

measure-theory

asked 26 mins ago Atul Anurag Sharma 103

0

votes

0

answers

3

views

Is a solution of an elliptic PDE constant if all of its derivatives vanish at a point? (in analogy to unique continuation principle)

pde harmonic-functions analyticity analytic-continuation sturm-liouville

asked 27 mins ago stewori 171

0

votes

1

answer

26

views

Bertrand's Paradox confusing

probability geometry probability-distributions

answered 27 mins ago David K 60.1k

0

votes

0

answers

3

views

Question about the limit of the variance of a band-pass limited white noise

integration signal-processing variance correlation noise

asked 28 mins ago claudia 6

0

votes

0

answers

9

views

$\int_E f_n = $

real-analysis measure-theory lebesgue-measure

asked 28 mins ago Jordan Reed 55

0

votes

0

answers

24

views

Where is $\sqrt{2-z}$ analytic

complex-analysis

modified 28 mins ago Jess 307

1

vote

0

answers

16

views

Computing $\lim_{T\rightarrow\infty} \frac{1}{T}\int_0^T (2^x \alpha - \lfloor 2^x \alpha \rfloor) dx$

integration sequences-and-series number-theory limits

modified 29 mins ago Julian Mejia 3,767

1

vote

1

answer

7

views

Submonoid and abelian monoid

abelian-groups monoid

answered 30 mins ago Luiz Cordeiro 14.6k

1

vote

0

answers

26

views

+50

Convergence of probability of throwing at least $\lceil\frac{n}2\rceil$ heads in $n$ fair coin tosses

limits convergence

modified 32 mins ago Andrew Chin 1,166

1

vote

1

answer

16

views

$a_n=O(\frac{1}{n}),\ \frac{\sum_{k=1}^nS_k}{n}$ converges $\Rightarrow S_n$ converges

sequences-and-series limits asymptotics

answered 33 mins ago Mindlack 8,539

0

votes

1

answer

12

views

Doubt about substitution in integration in $\mathbb R^n$ polar coordinates

integration polar-coordinates

answered 33 mins ago Andrei 16.3k

0

votes

0

answers

16

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Curve whose signed curvature is $1 / 1 + s^2$

curves curvature parametrization

asked 35 mins ago vicase98 94

-1

votes

0

answers

13

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I have some troubles with proving this (heights of the triangle problem)

euclidean-geometry

modified 35 mins ago dumb_noob 11

3

votes

0

answers

30

views

Kernel of a specific homomorphism of modules $R[x,y]^2\to R[x,y]$

abstract-algebra modules

modified 39 mins ago Galois in the Field 333

0

votes

1

answer

13

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Make an equation true by moving one of the cards

puzzle

answered 40 mins ago Peter Foreman 16.2k

0

votes

0

answers

4

views

L-stones with quadrat

combinatorics

asked 41 mins ago 16yokidtryingtolearnmath 1

0

votes

1

answer

9

views

Please explain what this notation means in K-means clustering.

notation machine-learning

answered 42 mins ago Hyperplane 3,948

0

votes

1

answer

10

views

Rudin 4.17. Discontinuous points on a real function can only be at most countable

continuity first-countable

answered 42 mins ago Mohammad Riazi-Kermani 53.3k

0

votes

0

answers

11

views

Substitution in Linear Algebra

linear-algebra systems-of-equations substitution

asked 43 mins ago user10478 629

0

votes

1

answer

24

views

Valuations on Dedekind domains and problem

abstract-algebra field-theory valuation-theory dedekind-domain

modified 44 mins ago reuns 28.3k

0

votes

1

answer

13

views

Sum of two hermitian matrices

linear-algebra matrices

answered 46 mins ago Chappers 58.5k

0

votes

1

answer

11

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Question related to Banach spaces and the unit sphere.

functional-analysis

modified 50 mins ago Marios Gretsas 9,620

1

vote

2

answers

26

views

A restaurant has a fixed price of $36 for a complete dinner…

algebra-precalculus

modified 51 mins ago guest 1

0

votes

1

answer

22

views

Multiple choice on group $Z[x]$

group-theory group-isomorphism

modified 54 mins ago KNilesh 1,117

0

votes

0

answers

9

views

order of zeroes for bounded function

complex-analysis

modified 1 hour ago Thesinus 577

1

vote

1

answer

28

views

Use $T(x,y)=\begin{pmatrix}\frac{\sin x}{\cos y}\\ \frac{\sin y}{\cos x}\end{pmatrix}$ to evaluate $\sum_{n=1}^{\infty}\frac{1}{n^2}$

real-analysis sequences-and-series analysis

answered 1 hour ago Jack D'Aurizio 300k

1

vote

1

answer

19

views

Uniform integrability of random variables $~e^{(X_1+X_2+…+X_{n-1}+X_n - \frac{n}{2})}$

probability-theory uniform-integrability

modified 1 hour ago nmasanta 3,746

0

votes

3

answers

25

views

Summation or Algebra?

summation

modified 1 hour ago Robert Z 113k

1

vote

0

answers

24

views

Hurwitz Polynomial - Why does continued fraction expansion work?

complex-analysis control-theory network

modified 1 hour ago NoChance 5,044

0

votes

0

answers

18

views

Finding the terms of a continued fraction

number-theory elementary-number-theory fractions supremum-and-infimum

modified 1 hour ago Will Jagy 109k

1

vote

0

answers

18

views

Difference between $f:\mathbb{R}\times\mathbb{R}^n\to\mathbb{R}^n$ and $f:\mathbb{R}^n\to\mathbb{R}^n$

functions

asked 1 hour ago Archimedess 41

1

vote

0

answers

23

views

H is a subgroup of G. Show that a coset of H is not a subgroup of G unless it is equal to H

abstract-algebra group-theory

asked 1 hour ago Marco Esquandolas 67

1

vote

1

answer

8

views

two equivalent projections in matrix algebra

operator-theory operator-algebras c-star-algebras

answered 1 hour ago Aweygan 16.6k

2

votes

0

answers

15

views

Consider the IVP $ x'=h(t)g(x),\quad x(t_0)=x_0$.

ordinary-differential-equations

modified 1 hour ago nmasanta 3,746

2

votes

0

answers

16

views

Wrong resolution leading to a correct answer

integration

asked 1 hour ago Gilled 11

2

votes

1

answer

42

views

Expectation of piece-wise objective function

probability expectation

answered 1 hour ago imu96 346

1

vote

1

answer

22

views

Proof of a weaker version of Hall's Marriage Theorem

discrete-mathematics elementary-set-theory graph-theory bipartite-graphs matching-theory

modified 1 hour ago Mike 6,473

0

votes

0

answers

16

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How to show that two equations equal each other?

trigonometry systems-of-equations

asked 1 hour ago White Wizard 1

-1

votes

0

answers

9

views

Find km/h with Kinetic Energy and mass?

mathematical-physics

asked 1 hour ago Yves Bonneau 1

2

votes

0

answers

17

views

If subsequences of $\{x_n\}$ converge to different values, prove $\{x_n\}$ diverges.

real-analysis

asked 1 hour ago MathsofData 29

0

votes

0

answers

23

views

Proof related with nature numbers

number-theory proof-verification natural-numbers

asked 1 hour ago Manx 412

1

vote

1

answer

25

views

Proving a constraint on $n$ when $n$ is prime

elementary-number-theory

modified 1 hour ago Peter 52.3k

1

vote

0

answers

10

views

What is divergence and curl of vector $R \times (A \times R)$

vectors vector-analysis divergence

modified 1 hour ago Robert Lewis 52.5k

0

votes

1

answer

13

views

Maximum volume of the package?

limits functions

answered 1 hour ago Andronicus 522

0

votes

1

answer

10

views

Probability density of transformation of 2D normally distributed vector

probability normal-distribution transformation density-function

answered 1 hour ago kccu 14.2k

0

votes

0

answers

11

views

Inverse Square root of (diagonal + rank1) matrix?

linear-algebra

asked 1 hour ago Yaroslav Bulatov 1,938

0

votes

2

answers

21

views

Square Root Simplifying and Solving the problem to X

roots

answered 1 hour ago trancelocation 16.9k

3

votes

2

answers

40

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Symmetric matrix as a sum of symmetric matrices

linear-algebra combinatorics matrices algebraic-graph-theory combinatorial-geometry

answered 1 hour ago S. Dolan 3,891

0

votes

0

answers

8

views

SVD algorithm benchmark

linear-algebra numerical-linear-algebra least-squares svd

asked 1 hour ago Mehdi asselman 20

-2

votes

0

answers

13

views

graph of $-\log_2\left(x-3\right)$, on desmos why is there a discontinuity?

graphing-functions

modified 1 hour ago Ertxiem 1,476

0

votes

0

answers

22

views

If $\|u\|=2, \|v\|=2$ and $u⋅v=3$, find $\|u+2v\|$

vectors

modified 1 hour ago Bernard 133k

0

votes

0

answers

5

views

A remark in a book of Gohberg-Krein

functional-analysis hilbert-spaces schauder-basis

asked 1 hour ago Andrei Kh 1,209

0

votes

0

answers

7

views

Finding the terms of a continued fraction using sup

number-theory elementary-number-theory fractions supremum-and-infimum

asked 2 hours ago JOJO 89

2

votes

0

answers

21

views

Prove that Hopf maps on $S^3, S^2$ and $\mathbb{C} \mathbb{P}^1$ are smooth submersions

differential-geometry manifolds smooth-manifolds projective-space

modified 2 hours ago C_M 1,567

1

vote

1

answer

16

views

Question about interchanging series and integral

real-analysis integration limits

answered 2 hours ago Marios Gretsas 9,620

1

vote

0

answers

14

views

Question about Wronskian.

ordinary-differential-equations

asked 2 hours ago AABBCC 23

3

votes

2

answers

35

views

How can I find an approximation of a smooth function $R^2 \to R^4$ such that when restricted to $S^1$ it is an immersion?

differential-geometry manifolds

modified 2 hours ago Matematleta 14.2k

2

votes

1

answer

26

views

Perpendicular bissector that pass through a fixed point

geometry

modified 2 hours ago WE Tutorial School 71

0

votes

0

answers

13

views

How To Find The Norm Of A Vector That Have Functions As Values?

vectors

asked 2 hours ago White Wizard 1

1

vote

0

answers

9

views

Number of ways constructing a $k$-clique.

graph-theory

asked 2 hours ago mkultra 315

0

votes

0

answers

9

views

Least Squares Problem with Summation

linear-algebra

asked 2 hours ago mattsprestige 21

4

votes

1

answer

18

views

Strictly Increasing Function with Derivative

real-analysis

modified 2 hours ago Luiz Cordeiro 14.6k

1

vote

0

answers

6

views

Plane cut the cone in perpendicular generators

analytic-geometry

asked 2 hours ago messi 27

0

votes

3

answers

124

views

Prove $\forall a,b \in \mathbb{Z}, 18a + 6b \ne 1$

elementary-number-theory divisibility

answered 2 hours ago Magagula Sabelo Patric 1

0

votes

1

answer

18

views

What does it mean to draw a graph on a surface?

general-topology graph-theory

modified 3 hours ago Henno Brandsma 132k

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