
Pressing the “solve” button computes the solutions of the cubic equation.

For the detailed description of Cardano's algorithm see To solve a cubic equation
Cardano 3x^3 - 10x^2 + x + 4 = 0
poly :
X :
Demo Project Cardano solver in Java script
Cardano 3x^3 - 10x^2 + x + 4 = 0
poly :
X :