A

David

Darling

Viviani's curve

Viviani's curve is the space curve that marks the intersection of the cylinder (x - a)2 + y2 = a2 and the sphere x2 + y2 + z2 = a2. It is given by the parametric equations:

 

x = a(1 + cos t)
y = a sin t
z = 2a sin(½ t).