Quadratic Equation Solver

Solve ax² + bx + c = 0 and see the discriminant and the real solutions. The calculation happens in your browser.

How to use it

1. Rewrite your equation so one side is zero.
2. Enter a, b and c, including minus signs.
3. Read the discriminant and the solutions.

Examples

• x² − 5x + 6 = 0: discriminant 1, so x = 3 or x = 2.
• x² − 4x + 4 = 0: discriminant 0, one repeated root, x = 2.
• 2x² + 3x − 2 = 0: discriminant 25, so x = 0.5 or x = −2.
• x² + 2x + 5 = 0: discriminant −16, no real solutions.

Good to know

The solver uses x = (−b ± √(b² − 4ac)) ÷ 2a. If a is zero the equation is linear, and the tool says so. When the discriminant is negative the tool reports that there are no real solutions and does not show the complex roots. To check an answer, put it back into the equation.

See how to solve a quadratic equation for the method.

FAQs