x(t) = 2 a t y(t) = a t^2

y = x^2/(4 a)

r(θ) = 4 a tan(θ) sec(θ)

(for a parabola opening upward with vertex at the origin and semilatus rectum 2a)

algebraic | conic | parametric | quadratic

d = 2

e = 1

{(0, a)}

L = 2 a

p = 2 a

y = -a

evolute | semicubical parabola involute | parabola involute