Chasles's Theorem
If two projective Pencils of curves of orders 
and 
have no common curve, the Locus of theintersections of corresponding curves of the two is a curve of order 
through all the centers of eitherPencil. Conversely, if a curve of order contains all centers of a Pencil of order to themultiplicity demanded by Noether's Fundamental Theorem, then it is the Locus of the intersections of correspondingcurves of this Pencil and one of order projective therewith.
References
Coolidge, J. L. A Treatise on Algebraic Plane Curves. New York: Dover, p. 33, 1959.
- Design
- Design Theory
- de Sluze Conchoid
- de Sluze Pearls
- Desmic Surface
- Destructive Dilemma
- Determinant
- Determinant (Binary Quadratic Form)
- Determinant Expansion by Minors
- Determinant (Knot)
- Determinant Theorem
- Developable Surface
- Deviation
- Devil on Two Sticks
- Devil's Curve
- Devil's Staircase
- Diabolical Cube
- Diabolical Square
- Diabolo
- Diacaustic
- Diagonalization
- Diagonal Matrix
- Diagonal Metric
- Diagonal (Polygon)
- Diagonal (Polyhedron)