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Quadratic Equation Calculator

Solve ax² + bx + c = 0 for real or complex roots.

Worth Knowing

The discriminant (b² − 4ac) reported alongside your roots tells you what kind of answer to expect before you even look at x₁ and x₂: a positive discriminant means two distinct real roots, exactly zero means one repeated real root (the parabola just touches the x-axis at a single point), and a negative discriminant means the parabola never crosses the x-axis at all — its roots are a complex conjugate pair, which is what this calculator returns in that case rather than an error.

How to Use

  1. Enter a into the first field of the Quadratic Equation Calculator.
  2. Fill in the rest: b, c.
  3. Your result appears instantly as you type — there's no submit button or page reload.

Frequently Asked Questions