The Kind Cat
Reputation
38,975
97/100 score
 22h comment When does normal maximal subgroup have prime index? @NickyHekster he says $N$ is a maximal subgroup and is also normal, so t suffices to find a subgroup between $G$ and $N$ to contradict the maximality. 22h revised Structural Induction vs Normal (Mathematical) Induction added 85 characters in body 1d answered When does normal maximal subgroup have prime index? 1d comment When does normal maximal subgroup have prime index? exactly, I hope this helped. 1d comment Find the greatest common divisor of pairs of polynomials use the euclidean algorithm. 1d comment Wolfram|Alpha refuses to find the inverse of a large 6x6 matrix. " I have no idea why the technology I so desperately rely on is failing me now." relying on wolframalpha is for noobs. 1d comment When does normal maximal subgroup have prime index? have you tried using the correspondence theorem ? (sometimes called 4th iso theorem). 1d revised Show that a ring $R$ is a division ring if and only if, for each nonzero $a\in R$, there is a unique element $b\in R$ such that $aba = a$. added 4 characters in body 1d answered Show that a ring $R$ is a division ring if and only if, for each nonzero $a\in R$, there is a unique element $b\in R$ such that $aba = a$. 1d comment Prove that even $n$ can be partitioned to $\frac n2$ edges There is no $\frac{n}{2}$ becuase I swapped $n$ with $2n$. 1d comment Show that a ring $R$ is a division ring if and only if, for each nonzero $a\in R$, there is a unique element $b\in R$ such that $aba = a$. your solution has some flaws, like for example, why does such an $r$ exist? 1d comment Show that a ring $R$ is a division ring if and only if, for each nonzero $a\in R$, there is a unique element $b\in R$ such that $aba = a$. this was totally in my homework last year, let me see if I an remember 1d comment Prove that even $n$ can be partitioned to $\frac n2$ edges What part is causing you trouble? 1d answered Prove that even $n$ can be partitioned to $\frac n2$ edges 1d comment Let $G$ be a group of order $35$. Prove that $G \cong C_5 \times C_7$. if a subgroup is the only subgroup of its order then it is normal (because $gHg^{-1}$) is a subgroup with the same order as $H$) 1d revised Let $G$ be a group of order $35$. Prove that $G \cong C_5 \times C_7$. added 41 characters in body 1d answered Let $G$ be a group of order $35$. Prove that $G \cong C_5 \times C_7$. 1d comment How do I memorize mathematical proofs? Regarding the title: don't. 1d comment Graph Theory Proof of Website Clicks the website you are looking for is the website with the most links, this website can reach every other website with at most two clicks 1d revised Graph Theory Proof of Website Clicks added 74 characters in body