Formula and interpretation
A root of a polynomial P(x) is a value r for which P(r) = 0. For a quadratic ax²+bx+c=0, the discriminant b²−4ac indicates whether roots are distinct real values, repeated, or complex. Higher-degree equations may require numerical methods instead of a closed-form expression.
Worked quadratic example
Solve x² − 5x + 6 = 0. Factor the polynomial as (x − 2)(x − 3) = 0, so x = 2 and x = 3. Verify by substitution: 2² − 5×2 + 6 = 0 and 3² − 5×3 + 6 = 0. The solver should agree within numerical tolerance.