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age 19
visits member for 1 year, 8 months
seen Jul 14 at 4:38

Nov
7
comment Proving a set of functions from $\mathbb{N}$ to $\{1,0\}$ is countable
I tried looking at the private case of $|f^{-1}(\{1\})|=1$, But I'm not exactly sure how to write it. I understand that exists a function $g$ that maps every $n\in\mathbb{N}$ to the function for which $f(n)=1$, but how do I write it formally?
Nov
6
comment Proving a set of functions from $\mathbb{N}$ to $\{1,0\}$ is countable
Yep, these are the functions I try to prove there are countably infinite number of.
Nov
4
comment proving a simple function is bijective
If you'll look at the edit you'll see that's exactly where I was when asking in the first place. Well, it's my fault for trying to post questions while on a bus. I got my answer I think , ty...
Nov
4
comment proving a simple function is bijective
how do I explain this function is infact bijective?
Nov
3
comment Using the AM-GM inequality on 2 elements to deduce it's true for 4?
Got it, thanks...
Nov
2
comment In field ($F, +, \cdot$) , how can I prove $x^2 =1\implies x=1,-1$
still feeling stupid... Thanks for the quick response both of you.
Nov
2
comment In field ($F, +, \cdot$) , how can I prove $x^2 =1\implies x=1,-1$
wow, that was so simple I feel stupid now... Thanks