2,469 reputation
11442
bio website
location Canada
age 32
visits member for 2 years, 4 months
seen Jan 28 at 15:53

I hold a diploma in Network Administration (along with many industry certifications) and am currently studying Computer Science and Pure Math in University.


Mar
22
accepted Show that, if $f:A\to B$ is a function, with $A$ and $B$ being finite sets, and $|A|=|B|$, then $f$ is one to one iff $f$ is onto.
Mar
21
comment Show that, if $f:A\to B$ is a function, with $A$ and $B$ being finite sets, and $|A|=|B|$, then $f$ is one to one iff $f$ is onto.
I always forget that indirect proof, or proof by contradiction is a method to use... I always end up trying to go for a direct proof.
Mar
21
asked Show that, if $f:A\to B$ is a function, with $A$ and $B$ being finite sets, and $|A|=|B|$, then $f$ is one to one iff $f$ is onto.
Mar
20
asked Finding the inverse of a function
Mar
19
accepted Is the set of natural numbers closed under subtraction?
Mar
19
accepted What exactly is a lattice? And can somebody give an example of something that is not one?
Mar
19
comment What exactly is a lattice? And can somebody give an example of something that is not one?
Thanks. Never considered this. This is why I need to study more :)
Mar
19
accepted Let $A$ and $B$ be arbitrary sets. Show that $|A\times B|=|B\times A|$
Mar
19
comment Let $A$ and $B$ be arbitrary sets. Show that $|A\times B|=|B\times A|$
@tarab Sorry - I did get it. Just forgot to accept'
Mar
19
asked What exactly is a lattice? And can somebody give an example of something that is not one?
Mar
18
accepted Under what condition does $ac\equiv bc\ (mod\ n)$ imply that $a\equiv b\ (mod\ n)$?
Mar
18
asked Under what condition does $ac\equiv bc\ (mod\ n)$ imply that $a\equiv b\ (mod\ n)$?
Mar
12
asked Is the set of natural numbers closed under subtraction?
Mar
12
comment Find $q$ and $r$ with $0\leq r\leq |b|$, such that $a=qb+r$
Hmmm. I understand how the Euclidean algorithm works for finding relative primality and the GCD of two numbers... Is this similar? It didn't appear to be when I first read it.
Mar
12
asked Find $q$ and $r$ with $0\leq r\leq |b|$, such that $a=qb+r$
Mar
11
asked How can i show that any two arbitrary intervals in the set of reals have the same cardinality?
Mar
11
asked Let $A$ and $B$ be arbitrary sets. Show that $|A\times B|=|B\times A|$
Mar
11
accepted Show that $\displaystyle\int_{-\pi}^\pi\sin mx\sin nx d x=\begin{cases}0&\text{if }m\neq n,\\\pi&\text{if }m=n\end{cases}$ using integration by parts
Mar
11
comment Show that $\displaystyle\int_{-\pi}^\pi\sin mx\sin nx d x=\begin{cases}0&\text{if }m\neq n,\\\pi&\text{if }m=n\end{cases}$ using integration by parts
@Lubin Well, I passed it in using the trig identity... It only said "Hint: Use integration by parts". So I didn't bother, since it was easier otherwise. If I lose marks then I lose marks.
Mar
11
comment Show that $\displaystyle\int_{-\pi}^\pi\sin mx\sin nx d x=\begin{cases}0&\text{if }m\neq n,\\\pi&\text{if }m=n\end{cases}$ using integration by parts
Why is $\sin{kx}$ and "odd" function?