Thomas Belulovich
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 Aug 5 awarded Yearling May 19 awarded Custodian May 19 revised If $f:X \to [0,1]$ be an onto continuous map and $\{f^{-1} (y)\}$ is compact then Is $X$ compact? Cleared up unclear language. Apr 23 answered Same Expansion for Different Functions! What's Wrong? Mar 2 revised If $\tan x=\sin x/\cos x$ then what is $\tan 3x$ equal to? fixed typo Dec 10 awarded Enlightened Dec 10 awarded Nice Answer Dec 9 awarded Caucus Nov 30 revised For $n\times n$ matrices $A,B,$ and $C,$ is it always true that $\mathrm{rank}(ABC)\leq\mathrm{rank}(AC)$? added 80 characters in body Nov 30 answered For $n\times n$ matrices $A,B,$ and $C,$ is it always true that $\mathrm{rank}(ABC)\leq\mathrm{rank}(AC)$? Nov 12 answered The jelly bean box problem Sep 24 awarded Autobiographer Aug 5 awarded Yearling Jul 3 comment Prove that this affine transformation is a translation I expect $\phi(P)P$ is the affine hull (line through) the distinct points $\phi(P)$ and $P$. This is why $\phi$ has to have no fixed points. Jun 26 comment Proving any N x M undirected two dimensional grid is bipartite This works. It's more concise to say that you are coloring based on the parity of $i+j$. Jun 26 comment Proving any N x M undirected two dimensional grid is bipartite You didn't color all the vertices -- only ones where one coordinate is even and the other odd. However, the idea is sound -- coloring based on parity will work here. Jun 26 comment Question from Munkres algebraic topology section 58: retractions It would probably good for your question to say what $j_*$ is (I assume the map induced on $\pi_1$, but it would be good to specify.) Jun 10 answered Shortest path between wikipedia articles May 23 awarded Nice Answer May 21 answered induced sequence exact