Right conoid
In geometry, a right conoid is a ruled surface generated by a family of straight lines that all intersect perpendicularly a fixed straight line, called the axis of the right conoid.
Using a Cartesian coordinate system in three-dimensional space, if we take the z-axis to be the axis of a right conoid, then the right conoid can be represented by the parametric equations:
where h(u) is some function for representing the height of the moving line.
Examples
A typical example of right conoids is given by the parametric equations
The image on the right shows how the coplanar lines generate the right conoid.
Other right conoids include:
Helicoid:
Whitney umbrella:
Wallis’s conical edge:
Plücker’s conoid:
hyperbolic paraboloid:
(with x-axis and y-axis as its axes).
See also
Conoid
Helicoid
Whitney umbrella
Ruled surface
External links
Hazewinkel, Michiel, ed. (2001), "Conoid", Encyclopedia of Mathematics, Springer, ISBN 978-1-55608-010-4
Right Conoid from MathWorld.
Plücker's conoid from MathWorld