1,151 reputation
729
bio website math.stackexchange.com/users/…
location Antarctica
age 79
visits member for 2 years, 2 months
seen Dec 16 at 5:42

Self-learning mathematics. Many thanks to those who make time to help others on the site.


Nov
21
awarded  Popular Question
Oct
6
awarded  Yearling
Jul
16
awarded  Civic Duty
Jun
28
awarded  Taxonomist
Jun
26
accepted Showing path connected matrices of a group $G$ is a normal subgroup
Jun
26
comment Showing path connected matrices of a group $G$ is a normal subgroup
In the first part, to allow for the inverse of $B$, do I need $\tau^{-1}$ to be continuous too or is it enough to say $\tau$ is continuous? Is this equivalent to saying if $B\in H$, we want to show $B^{-1}$ is in $H$? And you don't need to edit the post just to fix $I$, it's clear now.
Jun
26
asked Showing path connected matrices of a group $G$ is a normal subgroup
Jun
21
revised Showing the topologists sine curve is connected (slight variation)
added 70 characters in body
Jun
21
asked Showing the topologists sine curve is connected (slight variation)
Jun
19
accepted Understanding equivalent definitions of left cosets
Jun
19
revised Understanding equivalent definitions of left cosets
deleted 1 characters in body
Jun
19
asked Understanding equivalent definitions of left cosets
Jun
18
accepted Open sets in $\Bbb{R}^2$ and $\Bbb{R}^3$
Jun
17
comment Open sets in $\Bbb{R}^2$ and $\Bbb{R}^3$
So the unit intveral on the x-axis wouldn't be open in $\Bbb{R}^2$ right?
Jun
17
comment Open sets in $\Bbb{R}^2$ and $\Bbb{R}^3$
@Berci Thanks for that
Jun
17
comment Open sets in $\Bbb{R}^2$ and $\Bbb{R}^3$
Yes, but it is still a union of open balls. So in some sense, are open balls the basis of all open sets in $\Bbb{R}^2$?
Jun
17
asked Open sets in $\Bbb{R}^2$ and $\Bbb{R}^3$
Jun
17
comment Topologist's sine curve is connected
Doesn't disconnected mean that there are two disjoint open sets $A$ and $B$ such that the entire set $S$ is equal to $A\cup B$? But when you take your definitions of $A$ and $B$, the union of them is more than what is needed, no?
Jun
17
accepted Clarification on quotient groups
Jun
17
asked Clarification on quotient groups