DRF's user avatar
DRF's user avatar
DRF's user avatar
DRF
  • Member for 9 years, 5 months
  • Last seen more than a week ago
42 votes

Does mathematics become circular at the bottom? What is at the bottom of mathematics?

25 votes

I have a simple idea that I would like to make into a formula

18 votes

Is it mathematically valid to separate variables in a differential equation?

17 votes
Accepted

Why are vector valued functions 'well-defined' when multivalued functions aren't?

15 votes

What is an embedding degree of elliptic curve?

8 votes

Show that a ring is commutative if it has the property that ab = ca implies b = c when $a\neq 0$

8 votes

How do I prove that $ f(n) = (n + 1)! - 1 $ is an injective function?

7 votes
Accepted

What is a $P$-name in forcing theory

7 votes

Apparently sometimes $1/2 < 1/4$?

7 votes

Set of Elementary Real Numbers Without Elementary Combination

6 votes

Is the set of aleph numbers countable?

6 votes
Accepted

How do I show the existence of a weakly inaccessible cardinal is not provable in ZFC?

6 votes

When is it allowed to take a constant out of a series?

4 votes

is this set finite or infinite

4 votes
Accepted

Is 'difference of two squares' in this limit proof acceptable?

4 votes

cardinality of the set of real functions that approaches $0$ when $x\longrightarrow \infty$

4 votes

$\epsilon$ - $\delta$ definition of a limit - smaller $\epsilon$ implies smaller $\delta$?

4 votes

Unambiguous set abstraction (set-builder) notation with parameters

3 votes

The soccer splitting problem in arbitrary ring

3 votes

Single-Variable Integration Volume Problem. "When lengths change linearly, areas change quadratically"?

3 votes

Find an example of series which converges only absolutely on $\mathbb Q$

3 votes

Linear algebra doubt about the use of the word 'finite'

3 votes

What if there are two identities?

3 votes

Equality/Equivalence of functions

3 votes

Why do we calculate the median the way that we do?

3 votes

Why exactly does a function need to be continuous on a closed interval for the intermediate value theorem to apply?

3 votes
Accepted

Question on proof that $\operatorname{PowerSet}(X)\subset X $ is false for any $X$.

3 votes

If $A$ and $B$ are sets, then either $A \in B$ or $A\notin B$

3 votes

The cantor set is uncountable

3 votes

If $A$, $B$, $C$ are any infinite sets then is $|A|=|B|$ and $|A|=|C|$ $\Longleftrightarrow |A|=|B\cup{}C|$?

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