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J. Dionisio's user avatar
J. Dionisio's user avatar
J. Dionisio's user avatar
J. Dionisio
  • Member for 7 years, 3 months
  • Last seen more than a week ago
  • Porto, Portugal
9 votes
3 answers
2k views

Cantor Theorem assumes set is non-empty?

4 votes
4 answers
823 views

Irreducible polynomials of degree greater than 4 over finite fields

3 votes
1 answer
84 views

Maximum number of tangents to two circles in affine geometry

3 votes
2 answers
830 views

Proof that $2^{1/3} - 1/( 2 ^ {1/3} $) is irrational

2 votes
1 answer
1k views

Proof that if $3^n - 2^n$ is prime then $n$ is prime

2 votes
1 answer
1k views

Show that $f(x + 1/n) = f(x)$ for some $x$, given $f(0) = f(1)$ [duplicate]

2 votes
2 answers
189 views

Is $x^4 + 2x^2 - x + 1$ irreducible in $\mathbb Z_7[x]$?

2 votes
2 answers
100 views

what is the chance of a deck of cards not having adjacent suits or numbers?

2 votes
0 answers
91 views

What is the longest proposition reference chain in Euclid's Elements?

1 vote
1 answer
161 views

If $H(X,Y) = H(X) + H(Y)$ and $H(Y,Z) = H(Y) + H(Z)$, is $H(X,Y,Z) = H(X) + H(Y) + H(Z)$?

1 vote
1 answer
492 views

Proof for sphere eversion

0 votes
2 answers
832 views

Solving integrals using complex analysis

0 votes
0 answers
37 views

Example of inductive step working but not the base case [duplicate]

0 votes
0 answers
501 views

Why doesn't Cantor's Diagonal argument depend on the Axiom of Choice? [duplicate]

0 votes
0 answers
113 views

Markov Chains expected number of steps

0 votes
0 answers
45 views

Can we arrange an uncoutable amount of points on $\mathbb{R}^{2}$ so that their closure has dimension 0? [duplicate]

0 votes
1 answer
48 views

$|f '(x)| \le c$ for some $c<1$ implies a unique $a$ such that $f(a) = a$

0 votes
2 answers
86 views

Why can't i solve limits by definition like this?

0 votes
0 answers
52 views

Why is arc length related with scalar velocity?

0 votes
2 answers
43 views

Calculus 1 polynomials and derivatives [closed]

0 votes
1 answer
227 views

Inverse function of a product space

-1 votes
2 answers
704 views

What is {empty set} x something with the product topology?