Reputation
4,245
Next privilege 5,000 Rep.
Approve tag wiki edits
Badges
2 11 31
Newest
 Cleanup
Impact
~56k people reached

May
16
answered Connection of ideas of Measuring to the Measure theory .
May
16
comment What does a simple function actually mean?
By the way, a simple function is continuous iff $\partial A_{i}=\emptyset$ for all $i$, so they can represent other continuous functions than constants depending on the underlying topology. In $\mathbb{R}^{n}$ and Euclidean topology you're right though, since the only sets without boundary are $\mathbb{R}^{n}$ itself and $\emptyset$.
May
16
answered What does a simple function actually mean?
May
16
revised one more clock related challenge!
added latex symboling.
May
16
suggested approved edit on one more clock related challenge!
May
16
revised Find volume of a revolved solid by integrating wedges.
Corrected latex symboling
May
16
suggested approved edit on Find volume of a revolved solid by integrating wedges.
May
16
comment Condition for an interval being contained in a subset of $\mathbb{R}$
The terminology that you used works fine :-) About endpoints, do you mean 'endpoints' of $A$? In that case they may not exist or make sense if $A$ is unbounded or if $A$ is very messy. There is a notion of 'closure' of a set, which you may want to check out unless you're already familiar with it. Speaking of endpoints of an interval is fine though.
May
15
comment Regular, but not a normal topological space
Is this a homework assignment? And what have you tried so far?
May
15
suggested rejected edit on Regular, but not a normal topological space
May
15
revised Condition for an interval being contained in a subset of $\mathbb{R}$
added 318 characters in body
May
15
answered Condition for an interval being contained in a subset of $\mathbb{R}$
May
15
comment Is $M=\{(x,y)\in (0,\infty )\times\mathbb{R} : y=\sin(\frac{1}{x}) \}$ a closed set in space $((0,\infty )\times\mathbb{R} ,\rho_{e})$?
Sure; which ever you prefer :-)
May
15
awarded  Enthusiast
May
14
answered Is $M=\{(x,y)\in (0,\infty )\times\mathbb{R} : y=\sin(\frac{1}{x}) \}$ a closed set in space $((0,\infty )\times\mathbb{R} ,\rho_{e})$?
May
14
answered Finite measures are $\sigma$-finite
May
13
comment Show that the set of matrices such that $\det A \neq 0$ is open
Hint: The determinant function is continuous.
May
13
comment $A =\{ 1/(n+1): n \in \mathbb N \} $ is a nowhere dense subset
The closure of $A$ cannot be $\mathbb{Q}$ because $\mathbb{Q}$ is not closed while the closure of $A$ is.
May
6
comment Proving that a canonical projection is continuous in a product space
Usually the quotient space is given a topology by setting the quotient map continuous. What other information are you given?
May
6
answered Sequentially compact in a topological space?