In this x really indicates the arc whose length is x, and reference
should be made to the value of the radius of the circle from which the
curve is described. It will also be noticed that the equation only
covers the case in which the true divisions of the circle are laid off
on the line. If a multiple of such divisions are used, say n times, or
1-n times, then the equation should read
y = n sin( x ) or y = sin( x ) / n
Synonyms--Curve of Sines--Sinusoidal Curve--Harmonic Curve.