Quadratic Equation Solver
Solves ax² + bx + c = 0.
Result
- Roots
- x₁ = 3, x₂ = 2
- Discriminant
- 1
How to use the quadratic equation solver
- Enter the a.
- Enter the b.
- Enter the c.
- The results update as you type, or press Calculate.
- Read the roots first, then the supporting figures below it.
Formula
x = (−b ± √(b² − 4ac)) ÷ 2a.
Worked example
For example, with these inputs:
- a: 1
- b: -5
- c: 6
the calculator returns:
- Roots: x₁ = 3, x₂ = 2
- Discriminant: 1
Background
A quick mental estimate before calculating is a powerful check. If a room's floor area comes out at 4,000 square metres or a percentage comes out above 100% when it should not, you know to look again.
Calculators are best used to check working rather than replace it, especially for exams where method marks count. Work the problem by hand first, then confirm with the calculator.
Frequently asked questions
How does the quadratic equation solver work?
It applies this formula: x = (−b ± √(b² − 4ac)) ÷ 2a.
Can I use any units?
Yes, as long as every input uses the same unit. The answer will be in that unit (squared for areas, cubed for volumes).