Curves79 of 113
Semicubical parabola
William Neile, 1657
Its arc length, worked out by William Neile and published in 1657, made it the first algebraic curve to be rectified. It is the evolute of the parabola: the centres of the circles that fit a parabola best at each of its points lie on it, as drawn. Where its two branches meet, it has a cusp.
y² = a²x³
On mathcurve.com as Parabole semi-cubique