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The quadratic formula solves any equation ax² + bx + c = 0. The discriminant b²−4ac tells you how many real solutions exist before you solve.

Guide étape par étape

  1. 1Write in standard form: ax² + bx + c = 0
  2. 2Calculate discriminant: Δ = b² − 4ac
  3. 3Δ > 0: two real roots; Δ = 0: one root; Δ < 0: complex roots
  4. 4Apply: x = (−b ± √Δ) / 2a

Exemples résolus

Entrée
x²−5x+6=0
Résultat
x=3 or x=2
Δ=1>0, two roots
Entrée
x²−2x+1=0
Résultat
x=1 (repeated)
Δ=0, one root
Entrée
x²+x+1=0
Résultat
Complex roots
Δ=−3<0

Paramètres