Timeline for Stone-Weierstrass for monotone functions
Current License: CC BY-SA 3.0
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 4, 2012 at 20:33 | answer | added | Algernon | timeline score: 5 | |
| Jan 11, 2012 at 17:38 | vote | accept | CommunityBot | ||
| Jan 11, 2012 at 15:15 | comment | added | MTS | fedja, why don't you post your comment as an answer? The site works best that way - if there is an accepted answer it won't get randomly pushed back to the front page. | |
| Jan 11, 2012 at 14:54 | comment | added | Bill Johnson | While Yemon makes good points, I learned something from the thread and so upvoted the question as well as Anatoly's answer and fedja's comment. | |
| Jan 11, 2012 at 6:49 | answer | added | Anatoly Kochubei | timeline score: 8 | |
| Jan 11, 2012 at 4:46 | comment | added | Yemon Choi | I haven't downvoted, but the absence in the original question of motivation or background context, coupled with no hint of "here is what I know, here is what I have tried" means I'm not inclined to upvote either. (BTW, I didn't spot fedja's solution, but it certainly seemed a problem where the OP could have tried a bit harder, or at least shown more signs of prior work.) | |
| Jan 11, 2012 at 3:44 | comment | added | MTS | Wow, people are really piling on here. While the question does not give any motivation, it is clearly formulated and has a definite answer. As a non-analyst, the answer was not obvious to me. As fedja points out it turns out to not be that difficult, but I don't think that's immediately obvious. | |
| Jan 11, 2012 at 3:22 | comment | added | John Pardon | do you write the difference of two real numbers $x$ and $y$ as $x+(-y)$? | |
| Jan 11, 2012 at 0:29 | comment | added | user5810 | The point was to use only the field operations inside the absolute value. $\;$ | |
| Jan 11, 2012 at 0:25 | comment | added | fedja | It is "too easy". Basically it boils down to approximating $f$ by a smooth function $g$ with positive derivative, approximating $\sqrt {g'}$ by a polynomial $q$ on $[0,1]$, and putting $p=\int q^2$ on the line. There are many other solutions too. BTW, what's the point of writing $+((-p(x)))$ instead of the usual $-p(x)$? | |
| Jan 11, 2012 at 0:06 | comment | added | François G. Dorais | Best guess: manual spacing doesn't render as well in every browser. | |
| Jan 10, 2012 at 23:57 | comment | added | user5810 | ... so, is this too easy for MO? $\;$ If no, what were the downvotes for? $\;\;$ | |
| Jan 10, 2012 at 23:46 | history | asked | user5810 | CC BY-SA 3.0 |