Paul A Jungwirth
Reputation
Next privilege 250 Rep.
 Apr21 comment If $P = NP \cap coNP$, can $P \ne NP$? Whew, I'm glad you made that edit! :-) Apr21 accepted If $P = NP \cap coNP$, can $P \ne NP$? Apr21 awarded Commentator Apr21 comment If $P = NP \cap coNP$, can $P \ne NP$? @Qudit if your comment were an answer I could accept it! :-) Apr21 asked If $P = NP \cap coNP$, can $P \ne NP$? Jan23 awarded Student Jan23 accepted Why is every coset in G a subset of G? Jan23 comment Why is every coset in G a subset of G? Oh, you are right! p.19: "An operation $*$ on $A$ is a rule which assigns to each ordered pair $(a, b)$ of elements of $A$ exactly one element $a * b$ in $A$." So all operations are closed, but in addition a subgroup's operations are more tightly closed. Thanks! Jan23 comment Why is every coset in G a subset of G? @alex.jordan Really? My book says that a group means (1) $*$ is associative, (2) there is a $e$, and (3) every $a$ in $G$ has an inverse. A subgroup is a nonempty subset of a group that is closed with respect to multiplication and inverses. Is there a proof that every group is closed? There are groups that are not subgroups, right? Jan23 asked Why is every coset in G a subset of G? Mar31 awarded Popular Question Nov8 comment How many tries to get at least k successes? If I want to read more about the mathematics of binomial distributions, where is a good place to look? I've encountered them in statistics, but what would be the math course that introduces them? Probability? Nov8 awarded Scholar Nov8 awarded Supporter Nov8 comment How many tries to get at least k successes? Thank you! I'll need to digest the math a bit more, but the R function gives correct results for a few examples I tried. Nov8 accepted How many tries to get at least k successes? Nov8 comment How many tries to get at least k successes? Thank you for your help! I can't tell how this differs from what I wrote about finding $P$ for exactly $k$ successes, so how does it get me closer to a solution for at least $k$ successes? Perhaps you could expand on it a bit to help me understand? Nov7 comment How many tries to get at least k successes? In other words, I want to use some algebra to flip my equation from $P' = ...k...n...s...$ to $n = ...k...P'...s...$. Nov7 comment How many tries to get at least k successes? @Jean-Sébastien Suppose I want at least a 50% chance of getting $k$ or more successes. How many tries do I need so that the probability is 0.5? Nov7 comment How many tries to get at least k successes? Sure, it's easy enough to graph it, but what does that teach you? :-)