How real roots are found
For degree 1 and 2, exact closed-form solutions are used. For degree 3 and 4, the calculator combines closed-form Cardano / Ferrari with numeric refinement. For higher degrees, it uses Durand-Kerner iteration, then filters real roots within a tolerance.
Complex roots (where the imaginary part is non-trivial) are not displayed. Use a CAS like SymPy or Wolfram for symbolic complex roots.
Coefficient input
Enter coefficients with the highest degree first. Examples:
1, -6, 11, -6→ x³ − 6x² + 11x − 62, 0, -8→ 2x² − 81, 0, 0, 0, -1→ x⁴ − 1