Editing Equant (section)

=== Equation ===
The angle {{mvar|α}} whose vertex is at the center of the deferent, and whose sides intersect the planet and the equant, respectively, is a function of time {{mvar|t}} as follows:

: <math> \alpha = \Omega t - \arcsin\left(\frac{E}{\ R\ }\ \sin(\Omega t) \right) </math>

where {{mvar|Ω}} is the constant angular speed seen from the equant which is situated at a distance {{mvar|E}} when the radius of the deferent is {{mvar|R}}.<ref>See equation 8 in {{cite web |title=Eccentrics, deferents, epicycles and equants |website=Mathpages |url=http://www.mathpages.com/home/kmath639/kmath639.htm}} The quthor derives this in a complicated way using derivatives and integrals, but in fact it follows directly from equation 3.</ref>