Quadratic Discriminant
Calculate the discriminant b²−4ac for the quadratic ax²+bx+c.
How to use
- Enter coefficients a, b, and c.
- Calculate to inspect the discriminant Δ.
Capabilities and scope
The discriminant can classify how many real roots a genuine quadratic has.
How it works
Δ=b²−4ac; positive means two distinct real roots, zero a repeated real root, and negative no real roots.
Example
For a=1, b=−3, c=2, Δ=1.
Useful for
- Check whether a quadratic has real roots
- Classify a quadratic before applying the quadratic formula
Before you use it
- If a=0 the expression is not genuinely quadratic, so the usual quadratic interpretation of Δ does not apply.
Frequently asked questions
Does this also calculate the roots?
No. Its primary result is the discriminant; root values require the quadratic formula separately.