Polynomial Solver

Find the roots of polynomials up to degree 4.

Coefficients

Roots
Enter coefficients
x₁
x₂
x₃
x₄
Factored Form
Discriminant

Polynomial Roots

A root of a polynomial is a value x where f(x) = 0. The Fundamental Theorem of Algebra states that a polynomial of degree n has exactly n roots (counting multiplicity).

Quadratic Formula

x = (-b ± √(b² - 4ac)) / 2a

Discriminant

For ax² + bx + c = 0: Δ = b² - 4ac

  • Δ > 0: Two distinct real roots
  • Δ = 0: One repeated real root
  • Δ < 0: Two complex conjugate roots

Cubic and Quartic

Cubic equations have exact solutions (Cardano's formula). Quartic equations can be solved using Ferrari's method. Higher-degree polynomials typically require numerical methods.