Step by step
- Write the equation as ax² + bx + c = 0 and read a, b and c.
- Work out the discriminant b² − 4ac.
- Plug into x = (−b ± √disc) / 2a for both signs.
At a glance
| Part | Meaning | In x² − 5x + 6 = 0 |
|---|---|---|
| a, b, c | Coefficients | a = 1, b = −5, c = 6 |
| b² − 4ac | Discriminant | 25 − 24 = 1 |
| (−b ± √1)/2 | The two roots | x = 3 and x = 2 |
Related questions
Does it work for every quadratic?
Yes, as long as a is not zero.
Is it the same as Bhaskara's formula?
Yes, Brazil calls it the Bhaskara formula.
Can I check my answer?
Substitute each root back into the equation; it should give 0.
More questions: quadratic formula calculator
- How to solve a quadratic equation with the formula, step by step
- What is the discriminant (b² − 4ac)?
- What if the discriminant is negative? Complex roots explained
- What is the quadratic formula used for in real life?
- How to find a, b and c in a quadratic equation
- Quadratic formula examples and practice problems
- How is the quadratic formula derived? Completing the square
- Who invented the quadratic formula? History and the name Bhaskara
- How to use the quadratic formula on a calculator (TI-84, Casio)
- How to solve a quadratic equation in Excel
Open the full quadratic formula calculator →
Updated November 14, 2026.