Polynomial.discr_of_degree_eq_two

∀ {R : Type u_1} [inst : CommRing R] {f : Polynomial R},
  f.degree = 2 → f.discr = f.coeff 1 ^ 2 - 4 * f.coeff 0 * f.coeff 2

Standard formula for the discriminant of a quadratic polynomial.

Defined in: Mathlib.RingTheory.Polynomial.Resultant.Basic
Cited by: 1 results in Mathlib
Foundations: Depth 109 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes: CommRing

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