Glen Wheeler
Reputation
1,795
Next privilege 2,000 Rep.
 Feb3 comment maximum number of collinear points? But how can you both 'have solved' the problem and not be able to write the precise statement for us? We do not want 'an idea about the problem'. Feb3 comment Supremum length of space curves contained in the open unit ball having always less than unity curvature Perhaps I am being dense, but doesn't your lemma require $y$ to be disjoint from the image of the curve? Feb2 comment A proof of the Isoperimetric Inequality - how does it work? Alex is right: all the work is being done here by Green's theorem. That said... Perhaps one thing which could be confusing is the apparent importance of the circle C. The circle is used only as a stepping stone to travel from an expression for the area to an expression for the perimeter. The reason the $r$ drops out at the end is exactly that your choice of projection doesn't really matter. If the circle is very small then the estimate from Green's theorem takes this into account already. Feb1 comment Transformation T is… “onto”? @Pete/Sebastion: oh dear. I completely failed to remember this! too long since I taught L^p theory... Apologies Brian! Jan31 comment Transformation T is… “onto”? @Brian: I am pretty sure that an element of $L^2$ certainly is a function. Perhaps you meant not necessarily continuous? Jan31 answered Linear Algebra — Why is this theorem significant? Jan21 comment On differentiability and definition of derivative in case of uniform convergence May I ask, what is the sequence of functions exactly? Perhaps this will help clarify the point at hand. Jan21 revised On differentiability and definition of derivative in case of uniform convergence added 3 characters in body Jan21 answered On differentiability and definition of derivative in case of uniform convergence Jan19 awarded Commentator Jan19 comment Why does every 7-manifold bound an 8-manifold? Apologies for my earlier ignorant response. I didn't appreciate the intricate nature of the question. I would also like to second Jim's suggestion: it might be profitable to post this at MathOverflow. Jan19 awarded Peer Pressure Jan14 comment How to create a graycode of N bits with a code-agnostic iteration function @TonyK: I know, I like to think of them as (Hamiltonian) cycles in an n-cube. I was suggesting that perhaps frLich could improve the question. I did a little work on Gray codes, but it isn't computationally efficient and so not applicable to this question. Shame ;). Jan13 comment How to create a graycode of N bits with a code-agnostic iteration function You should define what a Gray code is, at least. Jan13 answered How does one characterize surfaces with constant nonzero Gaussian and mean curvature Jan7 comment Are there any countable Hausdorff connected spaces? I believe Qiaochu is only implying that my 'singleton' response was not a valid example. Jan7 comment Are there any countable Hausdorff connected spaces? I thought so :). I added a reference that you might find interesting. In general these things are quite strange. But I guess you can get more out of Theo's link. Jan7 revised Are there any countable Hausdorff connected spaces? added 139 characters in body Jan7 answered Are there any countable Hausdorff connected spaces? Dec10 answered Does saying “to negate a sign of a const term” has a meaning