Martin Sleziak
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 25m revised Extending functions from $(a,b)$ to $[a,b]$. edited tags 2h revised prove that $\exists\ \epsilon>0$ such that $\forall x\in [0,1] : f(x)>x+\epsilon$ TeX: \lim; edited tags 4h awarded Enlightened 5h awarded Nice Answer 6h revised Let $X=\{0,1\}$ be equipped with the indiscrete topology; Why is every $f:Y \to X$ continuous? minor typos 11h revised Math-english for non-natives: What does “supported in” mean? edited body 11h revised Math-english for non-natives: What does “supported in” mean? edited tags 12h revised Maximum of function containing two variables $x$ and $y$ added (max-min) tag 12h comment Show that a differentiable function $f:\mathbb{R} \to \mathbb{R}$ has a global max in $a$ if $a$ is its local max I think that adding an exact reference rather than saying "my book" would also improve the question. (Not to mention that the phrase my book is somewhat ambiguous. It might mean a book your studying or a book you wrote.) 12h comment Show that a differentiable function $f:\mathbb{R} \to \mathbb{R}$ has a global max in $a$ if $a$ is its local max Did you want to write differentiable function rather than differential function? 12h revised Show that a differentiable function $f:\mathbb{R} \to \mathbb{R}$ has a global max in $a$ if $a$ is its local max added (max-min) tag 12h comment Prove that $(H,\circ)$ is a subgroup of the group $(G, \circ)$ @TobiasKildetoft You're probably right. I have removed the tag. 12h revised Prove that $(H,\circ)$ is a subgroup of the group $(G, \circ)$ rolled back to a previous revision 12h revised For a group $G$ and subgroup $H$, is $a \sim b \iff a^{-1}b\in H$ an equivalence relation even when $H$ is not normal? edited tags 12h revised Prove that $(H,\circ)$ is a subgroup of the group $(G, \circ)$ edited tags 13h revised mean time question added 2 characters in body; edited title 13h comment Find the limit of $\frac{(n+1)^\sqrt{n+1}}{n^\sqrt{n}}$. To see that $\left(\sqrt{n+1}^{\frac1{\sqrt{n+1}}}\right)^2 \to 0$ we can apply $\lim\limits_{n\to\infty} n^{1/n} =1$, right? Or, more precisely, $\lim\limits_{x\to\infty} x^{1/x} =1$. (This was shown here and in many other posts.) Or is there something more straightforward? 13h revised Solving without induction show that $a_{n}=2n-1$ added 1 character in body 15h revised Why the number e(=2.71828) was chosen as the natural base for logarithm functions? added (e) tag 15h revised What's so “natural” about the base of natural logarithms? added (e) tag