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Adriano
  • Member for 9 years, 1 month
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16 votes
2 answers
4k views

Change of Variables in Limits (Part 1)

9 votes
3 answers
48k views

Necessary and sufficient conditions for differentiability.

4 votes
2 answers
315 views

Can the ceiling function be used to prove the Archimedean property?

3 votes
1 answer
277 views

Find the flaw in my proof that $z^2 =1$ has more than $2$ distinct solutions.

3 votes
1 answer
738 views

Using the definition of big-oh notation, show that for any $k,\gamma>1$, $n^k=O(\gamma^n)$.

3 votes
1 answer
234 views

Does $\neg(x > y)$ imply that $y \geq x$?

2 votes
2 answers
149 views

Any two points inside a circle are within a diameter of each other.

2 votes
1 answer
1k views

Does closure under the union and concatenation operations imply closure under the star operation?

2 votes
1 answer
135 views

Show that this type of function is surjective iff it's injective.

1 vote
1 answer
123 views

If $p$ is irreducible and $p \not \mid a$, then $\text{gcd}(p,a)=\pm 1$.

1 vote
2 answers
80 views

Are there $a,b,c,d \in \mathbb N$ such that $\frac{a + b}{a + b + c + d} < \frac{a}{a + c} < \frac{b}{b + d}$?

0 votes
3 answers
147 views

If $G$ is disconnected and the vertices $x,y$ are adjacent in $G$, then there is a vertex that isn't adjacent to $x$ and isn't adjacent to $y$.