Solve ax³+bx²+cx+d=0 for all three roots (real and complex) using the discriminant and Cardano/trigonometric method.. Cubic Equation Solver is a free online tool from the ToolsRift Math Calculators collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Enter the coefficients a, b, c and d and the solver returns all three roots along with the discriminant.
All three roots of ax³ + bx² + cx + d = 0, which may be three real roots or one real and two complex roots.
The discriminant determines the root type, then Cardano's formula or the trigonometric method computes the roots.
Yes — when the discriminant is negative, two of the roots form a complex-conjugate pair.