A function of the coefficients of a polynomial of one variable. It is essentially the product of all possible differences of roots of the polynomial. Therefore the discriminant is zero if and only if the polynomial has repeated roots.

a characteristic of a repeater signal from which the repeater can be identified

a quantity (usually invariant under certain classes of transformations) which characterizes certain properties of a quantity's roots

The expression b2 - 4ac of the quadratic formula that determines several characteristics of the roots of a quadratic equation.

(1) A rule for separating classes. (2) A rule for determining the number of solutions to a quadratic equation. (3) A statistic computed in program mCURVA as the difference between the first and second eigenvalues of the second partial derivative matrix; when used in conjunction with the Laplacian, this value categorises landform types.

In algebra, the discriminant of a polynomial is a certain expression in the coefficients of the polynomial which equals zero if and only if the polynomial has multiple roots in the complex numbers.