A polynomial discriminant is the product of the squares of the differences of the polynomial roots r_i. The discriminant of a polynomial is defined only up to constant factor, and several slightly different normalizations can be used. For a polynomial p(z) = a_n z^n + a_(n - 1) z^(n - 1) + ... + a_1 z + a_0 of degree n, the most common definition of the discriminant is D(p) congruent a_n^(2n - 2) product_(i, j i

cubic equation | polynomial | quadratic equation | quartic equation | resultant | root separation | Vieta's formulas