Free quadratic formula calculator for ax²+bx+c=0: shows discriminant Δ=b²−4ac, classifies two real / one real / complex roots, and lists real roots when they exist. Browser-based algebra helper—no login.
Enter coefficients a, b, and c. The tool computes Δ = b² − 4ac, classifies the root kind, and shows real roots when Δ ≥ 0, or a complex pair when Δ < 0. Coefficient a cannot be zero.
x = (−b ± √Δ) / (2a) with Δ = b² − 4ac. When Δ is negative, roots are written as a real part ± an imaginary part using √|Δ|.
Δ > 0: two distinct real roots. Δ = 0: one repeated real root. Δ < 0: a complex conjugate pair (no distinct real roots).
Then the equation is linear, not quadratic. The calculator shows an error asking for a ≠ 0 instead of silently solving bx+c=0.
Sibling tabs link Distance Calculator and Slope Calculator for coordinate work, plus Volume Calculator for 3D formula practice in the wider math-geometry cluster.
No. Math runs in your browser. Coefficients are not stored as uploaded file content for analytics.
Yes. Free with no login required on Power Tools.