Quadratic formula calculator
Solve ax² + bx + c = 0: real or complex roots, the discriminant, the vertex and a graph.
Graph
How it’s worked out
- Discriminant
- Δ = b² − 4ac
- Quadratic formula
- x = (−b ± √Δ) ÷ 2a
- Roots
Questions people ask
What is the quadratic formula?
For ax² + bx + c = 0, x = (−b ± √(b² − 4ac)) ÷ 2a. The part under the square root, b² − 4ac, is the discriminant.
What does the discriminant tell me?
Positive: two real roots. Zero: one repeated root (the parabola touches the x-axis). Negative: no real roots, two complex ones.