Step 1: How to use this calculator?

{'step': 1, 'description': 'Calculate discriminant: Î” = 7² - 4(2)(3) = 49 - 24 = 25'}

Step 2: How to use this calculator?

{'step': 2, 'description': 'Find √Î” = √25 = 5'}

Not checking if a=0 (would make it linear, not quadratic)

Forgetting the ± gives two solutions, not just one

Calculateur Equation Second Degre

Last updated: 2026-08-24

Calculateur Equation Second Degre — Calculez x = (-b ± √(b²-4ac)) / 2a. Exemple: 2x²+5x-3=0 (a=2, b=5, c=-3) = xââ€š=0.5 xââ€šâ€š=-3. Calculateur gratuit et précis, sans inscription.

Inputs

Result

Enter values and press Calculate

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How to use it

{'step': 1, 'description': 'Calculate discriminant: Î” = 7² - 4(2)(3) = 49 - 24 = 25'}
{'step': 2, 'description': 'Find √Î” = √25 = 5'}
{'step': 3, 'description': 'Calculate xââ€š\x81 = (-7 + 5) ÷ 4 = -0.5'}
{'step': 4, 'description': 'Calculate x₂ = (-7 - 5) ÷ 4 = -3'}

Common mistakes

⚠️ Not checking if a=0 (would make it linear, not quadratic)
⚠️ Forgetting the ± gives two solutions, not just one
⚠️ Misapplying signs when b is negative in the formule

Worked example

Solve the quadratic equation 2x² + 7x + 3 = using the quadratic formule

The solutions x1 ({x1}) and x2 ({x2}) are the roots where the parabola crosses the x-axis; discriminante ({discriminante}) determines solution type (positive=real, zero=real, negative=complex).

Input guide

Field	Typical range
a	Must be non-zero (otherwise not quadratic); typical: -100 to 100
b	Linear coefficient; typical: -1000 to 1000
c	Constant term; typical: -1000 to 1000