Frequently Asked Questions
Everything you need to know about the Cubic Equation Solver.
How does the cubic equation solver work?
Enter the four coefficients of your cubic and it finds all three roots using Cardano's formula, with the full working shown.
Is it free?
Completely free, no sign-up, downloads, or limits.
Does it find complex roots?
Yes, when the discriminant is negative, one real root and a complex conjugate pair are shown in a ยฑ bi form.
What is the discriminant used for?
It classifies the roots: three distinct real roots, a repeated real root, or one real root plus a complex pair.
What is Cardano's formula?
A classical method for solving cubic equations algebraically by first depressing the cubic to remove the squared term, then applying a formula involving the discriminant.
Does it show a graph?
Yes, the cubic curve is plotted with real roots marked where it crosses the x-axis.
Can it handle non-integer coefficients?
Yes, any real coefficients are accepted.
Are results exact or rounded?
Clean rational roots are shown exactly; irrational or complex roots are rounded to a sensible precision.
Is my data stored?
No; everything runs in your browser and isn't stored or sent.
Does it work on mobile?
Yes, fully responsive; the graph and steps adapt to smaller screens.