Talk:Pole and polar

reciprocity theorem

The assertion that "if a point Q is on the polar line A of a point P, then the point P must lie on the polar line B of the point Q" is sometimes called the reciprocity theorem. Does it deserve its own page Reciprocity theorem (projective geometry) ? Tkuvho (talk) 14:55, 14 September 2010 (UTC)

Your question is a good one and may encourage someone to write an article like Wikipedia:Notability (numbers), but for theorems instead. Since "Pole and polar" is a relatively short article and can use some work, your edit naming the Reciprocity Theorem in the Properties section would be appreciated. Naturally you have a source that can be cited. Alternatively, if the Reciprocity Theorem has inspired a line of research with several sources and implications, then an article on that subject would also be nice.Rgdboer (talk) 02:03, 15 September 2010 (UTC)

According to Edwards (see article references), reciprocity is a fairly broad phenomenon. In projective geometry, it appears for example as a property of points in an involution. Polar reciprocity, as per the above theorem, is another example (or possibly a specific example of reciprocity in an involution, I forget). Edwards devotes some pages to these ideas, there is a chapter on polarisation, so I'd suggest that as a useful source book. Whether there is enough in there to justify a separate article on the reciprocal properties of polar constructions, I would doubt. — Cheers, Steelpillow (Talk) 16:52, 23 August 2022 (UTC)

Standard form for the equation of a conic section

Is it not possible, inside Wikipedia, to agree about a standard form for the equation of a conic section? In each of the following articles the form used for the equation of a conic section is different.

http://en.wikipedia.org/wiki/Conic_sections#Cartesian_coordinates

http://en.wikipedia.org/wiki/Pole_and_polar#General_conic_sections

http://en.wikipedia.org/wiki/Degenerate_conic#Discriminant

Jhncls (talk) 16:39, 13 August 2013 (UTC)