Crunode
From Wikipedia, the free encyclopedia
A crunode is a point where a curve intersects itself so that both branches of the curve have distinct tangent lines.
A curve may intersect itself several times at one point and have distinct tangents at the point. For example r=cos(3θ), in polar coordinates, intersects itself three times at one point, with distinct tangents for each branch.
An acnode is a singularity of the function, where both partial derivatives <math>\partial f\over \partial x</math> and <math>\partial f\over \partial y</math> vanish. Further the Hessian matrix of second derivatives will be negative definite.
[edit] See also
- Singular point of a curve
- Acnode
- Cusp or Spinode
- Tacnode
