1,698 reputation
929
bio website molinajosue.blogspot.com
location Houston, TX
age 25
visits member for 2 years, 5 months
seen 2 days ago

One Thousand Birds


Sep
29
awarded  Popular Question
Sep
26
comment How should I begin when trying to determine a proposition whose truth value is unknown?
Don't think of mathematics as having some sort of rule book, but pure logic instead. Things need to make sense before you proceed!
Sep
16
awarded  Popular Question
Sep
12
revised How to integrate $\cos(\theta)\exp(i a \sin(\theta-\phi))$
The OP was fixed.
Sep
12
suggested suggested edit on How to integrate $\cos(\theta)\exp(i a \sin(\theta-\phi))$
Aug
26
asked Simple Algorithm Running Time Analysis
Jul
23
accepted The union of a sequence of countable sets is countable.
Jul
23
comment The union of a sequence of countable sets is countable.
I get your idea. :-) I am just trying to wrap my head around the technicalities. And thank you!
Jul
23
comment The union of a sequence of countable sets is countable.
I was indeed trying to obtain $(1)$ but did not know how to. I am a little confused: if for $x_{k,l}$ I take $k=1$ and $l=1$, which is the first term of the sequence, then, according to your last expression, $x_{k,l}$ would be the $3$rd term?
Jul
23
comment The union of a sequence of countable sets is countable.
@PeterTamaroff, $\mathcal S$ is an implementation of the diagonal argument.
Jul
23
asked The union of a sequence of countable sets is countable.
Jul
22
accepted Fourier Series Definition Question
Jul
22
accepted The union of a sequence of infinite, countable sets is countable.
Jul
22
comment Every infinite subset of a countable set is countable.
I like this. :-) Thank you!
Jul
22
accepted Every infinite subset of a countable set is countable.
Jul
22
asked Every infinite subset of a countable set is countable.
Jul
20
accepted Theorem 2.13 in Walter Rudin's Principles of Mathematical Analysis
Jul
20
comment Theorem 2.13 in Walter Rudin's Principles of Mathematical Analysis
Thank you for the clarification! That makes sense. For a moment there, I thought that with equivalent he meant equal.
Jul
20
asked Theorem 2.13 in Walter Rudin's Principles of Mathematical Analysis
Jul
19
comment The union of a sequence of infinite, countable sets is countable.
@HagenvonEitzen, how did you conclude that $\mathbb N\to S$?