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1d
comment If an inequality is true for all natural numbers, is it necessarily true for all real numbers inbetween?
@SteveJessop oops! Blunder of the year award goes to...
1d
comment If an inequality is true for all natural numbers, is it necessarily true for all real numbers inbetween?
isn't it exactly $0$ for all integer $n$?
2d
comment Why is it that if I count years from 2011 to 2014 as intervals I get 3 years, but if I count each year separately I get 4 years?
@FreeAsInBeer I was making a joke :)
2d
comment Why is it that if I count years from 2011 to 2014 as intervals I get 3 years, but if I count each year separately I get 4 years?
@FreeAsInBeer I don't know about you, but I had my 1-year anniversary lunch on my first day.
Jul
25
comment Is this proof of the fundamental theorem of calculus correct?
@Semiclassical Are there are proofs for plausibility which we don't have proofs of truth for? Or better yet, that we have proofs to the contrary?
Jul
25
answered Hide my invoice number
Jul
25
comment Hide my invoice number
@flawr A hash function is not particularly secure here. If the user knows that it's to hide incremental numbers, they can just enumerate the incremental numbers and hash them until they get a match. This is very feasible. It may seem like nobody is going to guess or try this, but if you ask the people security stackexchange you'll hear them say "Security by obscurity, is not security at all".
Jul
24
awarded  Pundit
Jul
23
comment What are some 'conceptualizations' that work in mathematics but are not strictly true?
en.wikipedia.org/wiki/Bohr_model is not strictly true. But it's taught in every grade 10 science class AFAIK
Jul
22
comment Making 400k random choices from 400k samples seems to always end up with 63% distinct choices, why?
@JyrkiLahtonen Does it approach 1/e as N -> infty?
Jul
17
comment Free throw interview question
This answer doesn't address that if your chance of making the shot is more than 67%, then you would rather the 20/30 case. This answer seems to suggest that you always take the first choice.
Jul
15
comment What is the probability that A will win…
@user21820 it's generally accepted that if each trial has a fixed, non-0 chance of ending, then the probability of ending is indeed 1. This "reroll" or "redo" logic, is intuitive, and widely used. In ANY case. The method is not wrong. At best you can say the justification is incomplete. But saying: "The probability of eventually rolling one of these cases is 1 as $\prod_0^\infty{25/36}=0$"
Jul
15
comment What is the probability that A will win…
@user21820 That is an entirely different game. The fact that it works with the other answers is irrelevant. In the current game, enumeration works. Period. The game goes on forever with probability 0 as long as you use the same dice on each iteration. And this works for any number of sides on the die. As long as its fixed.
Jul
14
comment Can a coin with an unknown bias be treated as fair?
This doesn't work for all biases(fails with bias 100% and 0%). And all biases close to that, make this impractical. The fun part is that the practical cases aren't likely to fall into these categories.
Jul
14
accepted Does taking the power set give you the “next biggest cardinal”
Jul
14
comment Does taking the power set give you the “next biggest cardinal”
Oh dear. It looks like I have a lot of reading ahead of me. As usual, the answer is never as simple as you'd like it to be ^.^
Jul
14
asked Does taking the power set give you the “next biggest cardinal”
Jul
14
comment What is the probability that A will win…
I really like this solution
Jul
14
comment What is the probability that A will win…
I arrived at 5/11 a little bit differently. I know the probability of 6 is 5/36. Probability of 7 is 6/36. Together these only make 11/36 possible cases. So we need to scale each probability up by 36/11 which simplifies to 5/11.
Jul
14
comment What is the probability that A will win…
@georg This answers a different question. And doesn't actually give a concrete answer to this question.