Ivan Shishkin, Rye (1878)

Problems

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Showing 87 problems

60

An integral limit

Riemann integration · Real analysis · 0 solved · Unreviewed

by Sequoia
0
14

Slicing chocolate bars

Other · 0 solved · Unreviewed

by Ancient Tree
0
34

When someone takes your sit in the train...

Probability on finite spaces · Combinatorics · 0 solved · Unreviewed

by Sequoia
0
18

Keeper's keys issue

Combinatorics · Probability on finite spaces · 0 solved · Unreviewed

by Sequoia
0
08

Une première définition géométrique de πFR

Geometry · 1 solved · Reviewed

antiquité
by goldfinch
1
37

Discrete topological manifolds

General topology · 0 solved · Unreviewed

by Ancient Tree
0
35

A cyclic system of congruences

Number theory · 0 solved · Reviewed

by Ancient Tree
0
45

Limit of norms

Real analysis · 0 solved · Reviewed

by Yggdrasil
2
14

How to split a chocolate bar

Combinatorics · 1 solved · Reviewed

by Sequoia
1
49

The Yoneda Lemma

Category theory · 0 solved · Reviewed

by AlexanderGrothendieck
0
54

Cauchy determinantal formula

Rings · Linear algebra · 0 solved · Unreviewed

by Sequoia
0
39

Quotient of a group and subgroup

Algebra · 1 solved · Reviewed

by Ancient Tree
1
57

Sequence of iterated sinus

Sequences and series · 0 solved · Unreviewed

by Sequoia
0
32

Cesaro Theorem

Riemann integration · Sequences and series · 0 solved · Unreviewed

by Sequoia
0
14

A simpler Pythagorean theorem

Geometry · spoiler domain hidden · 0 solved · Unreviewed

by Ancient Tree
1
24

Eulerian path in a finite graph

Graphs and discrete math · 0 solved · Reviewed

by Sequoia
0
20

Equality modulo pp and general equality

Number theory · 0 solved · Unreviewed

by Sequoia
0
15

Une première estimation de π dans la culture antique égyptienneFR

Geometry · Other · 0 solved · Unreviewed

antiquité
by goldfinch
0
20

Construction de la gamme chromatique en musiqueFR

Other · 0 solved · Unreviewed

musique
by goldfinch
1
05

Fraction over 100

Algebra · 3 solved · Reviewed

by Ancient Tree
0
05

Equality of areas in a triangle

Geometry · 2 solved · Reviewed

by goldfinch
2
24

Eigenvalues of orthogonal matrices

Linear algebra · 1 solved · Reviewed

by Ancient Tree
0
25

Eigenvalues of a weird matrix

Other · 1 solved · Reviewed

by Ancient Tree
0
42

Is the parabola reducible ?

Algebraic geometry · 0 solved · Unreviewed

by Ancient Tree
0
59

An equation solvable by radicals ?

Algebra · 0 solved · Unreviewed

by Ancient Tree
0
30

The trace inner product on matrices

Linear algebra · Euclidean vector spaces · 2 solved · Reviewed

by Nugget
0
21

The Monty Hall Paradox

Probability on finite spaces · 2 solved · Reviewed

by Nugget
0
24

The group of units of ℤ/nℤ

Number theory · Groups · 2 solved · Reviewed

by Nugget
0
42

7-adic year

Number theory · Real analysis · 0 solved · Unreviewed

by Ancient Tree
0
22

Magnitude of a root of a polynomial

Algebra · 1 solved · Reviewed

by Ancient Tree
1
51

Determinant of a gcd matrix

Linear algebra · Number theory · 1 solved · Reviewed

by Ancient Tree
1
63

A beautiful identity between polynomials

Combinatorics · 0 solved · Unreviewed

cycledecomposition in product of cyclespermutationspolynomials
by Sequoia
0
43

Divisors of zero in a commutative ring

Rings · 0 solved · Unreviewed

divisorsfinite ringring
by Sequoia
0
26

Real roots and derivative polynomial

Algebra · 1 solved · Reviewed

by Ancient Tree
0
17

Roots of the derivative of a quadratic polynomial

Algebra · 1 solved · Reviewed

by Ancient Tree
0
32

Interior of a vector subspace

Linear algebra · 1 solved · Reviewed

by Ancient Tree
0
52

Ring with cubic elements

Algebra · 0 solved · Unreviewed

by Ancient Tree
0
30

A reasoning on compactness

General topology · 1 solved · Reviewed

by Ancient Tree
0
21

Middle or sides ?

Probability and statistics · 1 solved · Reviewed

by Ancient Tree
0
12

An intimidating tower

Number theory · 1 solved · Reviewed

Trick question
by Ancient Tree
0
20

An unfamiliar inner product

Real analysis · Functional analysis · 1 solved · Reviewed

by Ancient Tree
1
40

Functor between integers with divisibility and groups

Category theory · 1 solved · Unreviewed

by Ancient Tree
0
45

Groups of order 2026

Algebra · 1 solved · Reviewed

by Ancient Tree
0
42

Group with all elements of order 2

Algebra · Groups · 0 solved · Unreviewed

abelian groupfinite groupgroup isomorphism
by Sequoia
0
20

Periodic function with a limit

Real analysis · 1 solved · Reviewed

by Ancient Tree
0
35

Groups of order 6

Representation theory · 0 solved · Unreviewed

by Ancient Tree
0
70

Polynomials that induce a surjection

Real analysis · 0 solved · Unreviewed

polynomialsurjection
by Sequoia
0
67

Wirtinger's inequality

Other · Riemann integration · Real analysis · 0 solved · Unreviewed

inequality
by Sequoia
0
15

Divisibility of an even number

Number theory · 1 solved · Unreviewed

by Ancient Tree
0
12

Consecutive integers and divisibility

Number theory · 1 solved · Reviewed

by Ancient Tree
0
38

Finite groups with 2 conjugacy classes

Algebra · 1 solved · Reviewed

by Ancient Tree
0
24

Groups with a single conjugacy class

Other · 1 solved · Reviewed

by Ancient Tree
0
10

Even-odd equality

Number theory · 1 solved · Reviewed

by Ancient Tree
0
60

Sine of a divisor of π

Algebra · 0 solved · Unreviewed

by Ancient Tree
1
10

Rationality of the golden ratio

Algebra · 1 solved · Reviewed

by Ancient Tree
0
25

Groups of order 41

Representation theory · 1 solved · Reviewed

by Ancient Tree
1
35

A necessary condition to be prime ?

Number theory · 1 solved · Unreviewed

arithmetic
by Sequoia
1
34

Gcd of two Mersenne numbers

Number theory · 0 solved · Reviewed

arithmeticgcd
by Sequoia
0
17

About tall people issues

Number theory · 0 solved · Unreviewed

arithmetics
by Sequoia
0
09

Five in a square

Combinatorics · 1 solved · Reviewed

by Sequoia
1
26

Forest tournament

Combinatorics · 0 solved · Reviewed

by Sequoia
0
20

Two equations with integer functions

Differential equations · 1 solved · Reviewed

functional equationintegers
by Sequoia
0
12

Quick exercise on set theory

Set theory · 1 solved · Unreviewed

intersectionset theoryunion
by Sequoia
0
45

A big weird limit

Real analysis · Power series · Real functions · 0 solved · Unreviewed

limitpower series
by Sequoia
1
07

Is it arithmetic ? Or geometric ?

Sequences and series · 1 solved · Unreviewed

recurrence relationsequence
by Sequoia
0
11

1,2,3... Shoot !

Combinatorics · 1 solved · Unreviewed

by Sequoia
2
50

Number of solutions of a Diophantine equation

Number theory · 1 solved · Reviewed

Diophantine equation
by Ancient Tree
0
29

Fixed points of a direct isometry

Algebra · 0 solved · Unreviewed

determinantfixed pointisometryrotation
by Ancient Tree
0
12

Linear maps of rank 0

Algebra · 1 solved · Reviewed

by Ancient Tree
0
10

Roots of a quadratic equation with a parameter

Algebra · 1 solved · Reviewed

polynomialquadratic equationroots
by Ancient Tree
0
65

Sequences whose terms are getting closer and closer

General topology · Connectedness · Sequences and series · 0 solved · Unreviewed

closed setsequencesubsequencesubsequential limit
by Sequoia
0
50

Determinant of circulant matrices

Linear algebra · 1 solved · Unreviewed

determinanteigenvaluesmatrices
by Sequoia
0
65

Lucas's theorem and an application

Sequences and series · 1 solved · Reviewed

convergenceconvex hullpolynomialsrootssequence
by Sequoia
0
54

Some bounded sequences that always converge

Sequences and series · 1 solved · Reviewed

bounded sequencescomplex numbersconvergencesequencesubsequence
by Sequoia
0
47

A cow issue

Combinatorics · spoiler domain hidden · 1 solved · Reviewed

matricesranksystem
by Sequoia
1
58

Probability of commuting in a finite group

Groups · spoiler domain hidden · 1 solved · Reviewed

finite groupprobability
by Sequoia
0
60

Limit of a sum of periodic functions

Real analysis · 1 solved · Reviewed

limitperiodic functions
by Ancient Tree
0
51

Finite groups with 3 conjugacy classesFeatured

Algebra · 0 solved · Reviewed

conjugacy classesgroup
by Ancient Tree
1
04

A perplexity of eggs

Number theory · 1 solved · Unreviewed

by Ancient Tree
0
35

Binomial coefficient identity with a bijection

Combinatorics · 1 solved · Reviewed

bijectionbinomial coefficients
by Ancient Tree
0
29

Determinant of a matrix with consecutive integers

Other · 1 solved · Reviewed

determinantmatrix
by Ancient Tree
0
10

Endomorphism with all eigenvectors

Algebra · 1 solved · Reviewed

eigenvectors
by Ancient Tree
0
09

A diagonalizable matrix ?

Algebra · 1 solved · Reviewed

by Ancient Tree
0
08

Four consecutive integers

Algebra · 1 solved · Reviewed

algebrafactorizationidentitiesintegers
by Ancient Tree
0
05

A price goes up and then down

Number theory · 2 solved · Reviewed

percentages
by Ancient Tree
0
05

Hidden fractions

Algebra · 2 solved · Reviewed

fractions
by Ancient Tree
0
35

Integers as consecutive sums

Number theory · 2 solved · Reviewed

by Ancient Tree
2