Complex roots of a cubic
- Author:
- James Ramsden
- Topic:
- Complex Numbers, Polynomial Functions, Root
Cubic roots (complex)
All cubics have at least one real root.
If there is only one real roots, there will be a quadratic factor. The dashed red parabola represents the equation of this quadratic reflected in it's turning point.
The intersection of this with the x-axis is marked on both the Cartesian and Argand diagram.
The complex roots correspond to the complex numbers at the top and bottom of a circle through these points on an Argand diagram.
(see also complex roots of a quadratic)