Space Curve

a curve in space. A space curve whose points do not lie in a single plane is said to be a twisted curve. Space curves have sometimes been called curves of double curvature.

If we wish to define a space curve in terms of Cartesian coordinates, we may view it as the intersection of two surfaces:

F(x, y, z) = 0 Ф(x, y, z) = 0

Alternatively, we may express it in parametric form:

x = ϕ(t) y = ψ (t) z = X(t)