Wikipedia:Reference desk/Archives/Mathematics/2006 December 14

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[edit] December 14

[edit] foot

what is the foot for my height 1.81m? is it 5 11?

google says 1.81m = 71.2598425 inches (71 = 5 × 12 + 11), so yes it's a little bit more than 5 feet 11 inches. --Spoon! 08:37, 14 December 2006 (UTC)
Which is written, btw, as 5'11". Black Carrot 16:33, 19 December 2006 (UTC)

[edit] a maths proof

there are six people in room. it is then certain that either: at least 3 people know one another OR at least 3 people dont know one another. how is it certain and proved?

See theorem on friends and strangers or Ramsey's theorem#Example: R(3,3)=6.--80.136.171.97 17:20, 14 December 2006 (UTC)

[edit] MathML in Wikipedia's Math Entries

Is it possible to use MathML to typeset mathemaitcal expressions in wikipedia?

Cmso 21:16, 14 December 2006 (UTC) Clare

Yes. You can see how to do so at Help:Displaying a formula. Titoxd(?!?) 21:34, 14 December 2006 (UTC)
Are you asking whether it is possible to enter formulas in MathML syntax into the source of articles and have it work like other formulas that were entered in TeX? or are you asking whether you can have formulas that were entered in TeX be displayed in MathML when you view it? I think for the former it is no (at least currently); but for the latter it may be yes. --Spoon! 01:10, 15 December 2006 (UTC)
As you may know, MathML has two styles, presentation and content. Neither may be used as Wikipedia input. For example, if you used
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <msup><mi>x</mi><mn>2</mn></msup>
  <mo>+</mo>
  <msup><mi>y</mi><mn>2</mn></msup>
</math>
hoping to get something like x2+y2, you would instead invoke the TeX-processing part of MediaWiki syntax. The results would be as follows:
  • < msup > < mi > x < / mi > < mn > 2 < / mn > < / msup > < mo > + < / mo > < msup > < mi > y < / mi > < mn > 2 < / mn > < / msup >
Probably not what you had in mind, eh? What is expected inside <math> tags is TeX markup like this:
<math> x^2 + y^2 \,\!</math>
The result of this is usually a PNG image of the formula:
  • x^2 + y^2 \,\!
There is supposed to be a preference setting, for readers who are logged in, under the "Math" tab, called "MathML if possible (experimental)". I don't think it works, since it requires the full page to be valid XML, which the rest of the software does not yet support. --KSmrqT 01:40, 15 December 2006 (UTC)