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32147
bio website phdcomics.com/comics.php
location Antarctica
age 94
visits member for 3 years, 3 months
seen 11 hours ago

MATH is a wonderful thing...

MATH is a really cool thing...

So get off your act lets do some MATH...

MATH, MATH, MATH, MATH, MATH...

http://www.youtube.com/watch?v=aa8U0nL-KXg


10h
awarded  Enlightened
10h
awarded  Nice Answer
23h
awarded  Constituent
Dec
15
reviewed Leave Open Let A be a nonempty set, and define function $f\colon A\to P(A)$ by $f(a)=\{a\}$. Show that $f$ is one-to-one but not onto.
Dec
15
reviewed Close Why does this circulating decimal become equal with a natural number?
Dec
15
reviewed Close Is a line just an infinitely large circle?
Dec
15
reviewed Close Solving Laplace's equation with separation of variables
Dec
15
reviewed Close Prove that a matrix T is non-singular iff ker (T) is zero
Dec
15
reviewed Close Prove that $\lim_{x \to \frac{2}{\pi}}\lfloor \sin \frac{1}{x} \rfloor=0$ in the $\epsilon$-$\delta$ way
Dec
15
reviewed Looks OK Let A be a nonempty set, and define function $f\colon A\to P(A)$ by $f(a)=\{a\}$. Show that $f$ is one-to-one but not onto.
Dec
15
reviewed Looks OK Let A be a nonempty set, and define function $f\colon A\to P(A)$ by $f(a)=\{a\}$. Show that $f$ is one-to-one but not onto.
Dec
15
reviewed Close Is every point in $\mathbb R$ a cluster point of $\mathbb R$?
Dec
13
revised Triangular inequality in weighted graphs
added 4 characters in body; edited title
Dec
11
reviewed Approve a question about relatively prime numbers
Dec
11
answered Prove or disprove: if $f$ is one-to-one and $g \circ f=h \circ f$ then $g=h$
Dec
10
comment Proving that a matrix has an inverse if and only if it RREFs to the identity matrix
You can refer to here: math.stackexchange.com/questions/164471/…
Dec
10
revised Proving that a matrix has an inverse if and only if it RREFs to the identity matrix
added 4 characters in body
Dec
10
answered Proving that a matrix has an inverse if and only if it RREFs to the identity matrix
Dec
8
awarded  Caucus
Dec
6
revised $f$ is a continuous function from $[0,1]$ to $\mathbb{R}$ s.t. $f(0)=f(1)$, prove $\exists c$ in $[0,\frac{1}{2}]$ such that $f(c)=f(c+ \frac{1}{2})$
added 80 characters in body