discriminant

/dɪˈskrɪmɪnənt/
noun
  1. A value used in mathematics (especially in quadratic equations) to determine the nature of the roots or solutions.
    • In the quadratic formula, the discriminant tells you if the equation has two real solutions, one solution, or no real solutions.
    • To find out if the equation can be factored easily, first calculate the discriminant.
    • The teacher explained that a discriminant of zero means the quadratic has exactly one real root.