Dan Piponi
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 Mar16 comment Domain of log and its derivative Did you mean to write $(0,\infty)$? The derivative clearly can't exist where the function being differentiated doesn't exist. Mar12 revised Examples where it is easier to prove more than less deleted 7 characters in body Mar12 answered Examples where it is easier to prove more than less Mar12 comment How to explain brackets to young students It sounds like this student has a very good understanding of brackets, something I've seen students struggle with. The problem here isn't with brackets, it's with addition. Mar12 comment Prove f(a)=f(b) if $\int_{-\infty}^{\infty}f(x)dx=1$ Very roughly: if f(a)>f(b) then shifting the region [a,b] left by δ would increase the integral by approximately δ(f(a)-f(b)) which would then allow you to shrink the length of the interval and still achieve the same integral. Mar3 awarded Popular Question Feb11 awarded Nice Answer Dec19 awarded Caucus Dec15 comment Are the real numbers really uncountable? @CarlMummert I'm not trying to say anything profound. Typically, in mathematics, when you want to pick a particular thing (in ZF, say) to talk about, you use a definition. Dec15 comment Proving $\int x \, \mathrm{d}y =xy- \int y \, \mathrm{d}x$ $\frac{dy}{dx}$ might look like a straightforward fraction, but it's not. You can't simply cancel $dx$'s without further justification. Dec3 comment Approximate solutions for quintic equation Nov14 awarded Necromancer Nov12 comment Cardinality of infinite sets - Help with intuition "why can't I do the exact same thing when dealing with the mapping between odds/integers?" Have you tried? Nov7 comment Function 'result arity' In my many years of mathematics I've never come across such a term. Oct26 answered Simplifying expressions when taking limit to infinity Sep18 revised why binary is read right to left added 12 characters in body Sep18 revised why binary is read right to left added 12 characters in body Sep18 answered why binary is read right to left Aug25 answered Does $G$ always have a subgroup isomorphic to $G/N$? Aug13 comment If $P(A) = 0$ is $A$ a null event? @user159813 The fact that the "event is a non empty set" does not make the event "non-null". The set of pairs of integers that sum to 13 is non-empty but it's impossible to roll 13 with two ordinary dice.