Talk:Strophoid

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This article incorporates text from the Encyclopædia Britannica Eleventh Edition, now in the public domain.

[edit] Expert

Before, the article consisted of just, "A curve: r = asin(α − 2θ) / sin(α − θ)". I added the 1911 Encyclopedia Britannica article, but the equations weren't scanned accurately. I looked up the equations on Google, but they didn't even seem close, so I removed the commentary. The article could use an expert to look it over. Perhaps someone can figure out what the 1911 EB was talking about. -- Kjkolb 10:37, 13 November 2005 (UTC)

Mathworld [1] lists it as "r = a cos(2θ) sec(θ)" which is the same upto rotation of cordinates. Having it as asin(...) could cause real confusion with the arcsin function. --Pfafrich 21:01, 31 December 2005 (UTC)

[edit] Foot of perpendicular

What is a foot of perpendicular? I couldn't find a definition in Wikipedia.

—Bartosz 01:51, 27 April 2007 (UTC)

updated the drawing --Duk 09:23, 30 November 2007 (UTC)