Quadratic Equation Solver

Find roots of quadratic equations ax² + bx + c = 0. Fast, free, and fully client-side.

Calculator Inputs

Coefficient a
Coefficient b
Coefficient c
Roots Result

How the Quadratic Equation Solver Works

A quadratic equation solver calculates the roots of second-degree polynomials of the form ax² + bx + c = 0. Depending on the discriminant value (b² - 4ac), the equation produces two real roots, one repeated real root, or two complex conjugate roots.

Formula

x = (-b ± √(b² - 4ac)) / (2a)

The discriminant Δ = b² - 4ac indicates real roots if Δ ≥ 0, or complex roots with imaginary unit i if Δ < 0.

Calculation Example

For x² - 5x + 6 = 0 (where a=1, b=-5, c=6): Discriminant is 25 - 24 = 1, yielding roots x = (5 + 1)/2 = 3 and x = (5 - 1)/2 = 2.

Frequently Asked Questions

What does a discriminant of zero mean?

It means the parabola touches the x-axis at exactly one point (a single repeated real root).

Can the coefficient a be zero?

No, if a = 0, the equation reduces to a first-degree linear equation (bx + c = 0).

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