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Poseidaan
  • Member for 2 years, 9 months
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4 votes
2 answers
102 views

Why is $\int x^2e^{x^2}\,d(x^2)$ not proper notation?

3 votes
2 answers
78 views

Is this a good way to differentiate between evaluation of a function at a specific point and multiplication.

2 votes
2 answers
38 views

Is it a general truth that when two equations can be described with the same sentence, only varying intonation they are equivalent?

1 vote
1 answer
30 views

How do I notate "the x-coördinate of $G^{-1}(z)$ for $z = G(x, y) : \mathbb{N}\times\mathbb{N} \to \mathbb{N}$

1 vote
1 answer
1k views

How can all matrices have a _unique_ reduced row echelon form?

1 vote
1 answer
81 views

If we want to use proof by contradiction, shouldn't we first proof that a statement is either true or false?

1 vote
1 answer
63 views

Why do we assume the set of all sets that do not contain themselves exists?

1 vote
0 answers
73 views

Why is my proof that $(A^m)^{-1} = (A^{-1})^m $ not rigorous?

1 vote
1 answer
46 views

How do we denote a surface embedded in four dimensions?

1 vote
2 answers
49 views

Why does $\cot(2\arctan(Ax))=\frac{1-(Ax)^2}{2Ax}$

1 vote
0 answers
52 views

Why does the Hodge-star of d$x$ equal d$y$ and not -d$y$?

0 votes
0 answers
56 views

Why does $\sum_{i=1}^{n-1} {n-1 \choose i} {m+1 \choose i+1} = \frac{(m+n)!}{m!n!}$

0 votes
0 answers
36 views

If $i^2=-1$ and $j^2=1, j \neq 1$ does there any literature for $k^2=0, k\neq0$ or even $k^2 = a, a \in \mathbb{R}, k \neq \sqrt{a}$?

0 votes
0 answers
85 views

What does $\bigoplus\limits_{\mathbb N} \mathbb Z$ mean?

0 votes
1 answer
99 views

Does there exist a function $f(x)$ such that $f'(x)$ exists for all $x \in A$ but $f'(x)$ is not continuous on $A$? [duplicate]

0 votes
3 answers
56 views

Why does $\sum_{k=0}^{n} (-1)^k {n \choose k} = 0$ if $n\neq 0$ and 1 otherwise? [duplicate]

0 votes
2 answers
37 views

How to properly write down $\frac{\partial}{\partial xy } f(xy, x^2+3y-2)$