[SciPy-user] how to resolve a cubic equation in scipy?

[Alan G Isaac]

On Fri, 16 May 2008, zhang chi apparently wrote:
> I want to resolve a cubic equation 1.2r^3  + r - 20 = 0. 

Cubics have a closed form solution:
http://mathworld.wolfram.com/CubicFormula.html

hth,
Alan Isaac