Discriminant calculator
Compute Δ = b² − 4ac and classify the number of real roots of a quadratic.
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Tool guide
Discriminant calculator: how it works
Practical information to understand the result and use this tool correctly.
About Discriminant calculator
Δ = b² − 4ac decides the nature of quadratic roots before you extract square roots.
Positive → two distinct real roots; zero → repeated root; negative → complex pair.
Fast for multiple-choice and graphing intuition when exact roots are optional.
How to use it
- 1Enter a, b, and c.
- 2Read Δ and the classification.
- 3Use the quadratic formula tool for explicit roots.
Frequently asked questions
- Only for quadratics?
- Yes — this calculator targets ax²+bx+c with a ≠ 0.
- a = 0?
- Then the expression is not quadratic; discriminant does not apply.