Reputation
Next tag badge:
393/400 score
114/80 answers
Badges
10 147 292
Newest
 Enlightened
Impact
~1.5m people reached

2d
revised Show the graph is Jordan region with volume 0
added 50 characters in body
2d
answered Show the graph is Jordan region with volume 0
2d
answered How does one find the Zariski closure of a set?
Jul
25
answered Show $f(x) = x\ln (1 + \frac{a}{x})$ is increasing when $x>0$ for any $a>0$ without using derivatives
Jul
25
answered Why is $\phi : \operatorname{Hom}(\mathbb{Z},G) \to G$ given by $ f \mapsto f(1)$ surjective?
Jul
25
answered Generalize multiples of $999…9$ using digits $(0,1,2)$
Jul
25
comment find formula for $P\land Q$ using $\uparrow$
@PandaDeTapas Tranlation according to "$P\uparrow Q$ means that not both of $P$ and $Q$ are true"
Jul
25
comment What's the image of $(a, b)$ under a typical $f$: $\mathbb{R}\longrightarrow\mathbb{R}$?
Whatever a generic function is, it seems that $(a,b)$ maps to a generic subset of continuum cardinality ...
Jul
25
comment Is it possible to define $x+x+x+x…x$ times?
In a way we could apply the chain rule to $\underbrace{u+u+\ldots +u}_{v}$ and need to consider $\partial \over \partial u$ as well as $\partial \over \partial v$. Even though the notation still doesn't make sense completely, for noninteger $v$ we obtain $u+v$, i.e., $2x$ as derivative
Jul
25
answered find formula for $P\land Q$ using $\uparrow$
Jul
24
comment Possible to turn any in-fix expression into post-fix with all values on one side?
Are we allowed to do 0 3 1 2 x - - or -1 3 1 2 x - x? Still, we'd get into trouble with $(1\times 2)+(3\times 4)$
Jul
24
answered Is 1 always an element in multiplicative group?
Jul
24
answered Calculate $\ln 97$ and $\log_{10} 97$
Jul
24
comment Labelled Venn-Diagram on Wolfram Alpha?
I assume that the graphic manipulation capabilities of whatever document software you use are sufficient to produce such a Venn diagram (also labelled) from scratch ...
Jul
24
comment Existence of groups with cyclic 2 Sylow subroups S o(S) = $2^k$
First of all there are the groups $\mathbb Z/2^k\mathbb Z\times H$ ...
Jul
24
comment A weird problem on expected value of a random variable
Do the $x_i$ have additional properties, e.g. are they equidistant?
Jul
24
comment How can we explain energy (or intensity) distribution mathematically?
Simple explanation: Shadow occurs when there is an opaque obstacle between light source and target surface ...
Jul
23
answered Sunflower Lemma - Allow Duplicates?
Jul
23
answered Constructing true metrics in infinite dimensional vector spaces?
Jul
23
comment Constructing true metrics in infinite dimensional vector spaces?
What do you mean with true metric?