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Reference table

Discriminant Table: Discriminant (b² − 4ac) by a

Reference table of discriminant (b² − 4ac) for Discriminant across a range of a values — exact, engine-computed figures you can read off at a glance.

By Vikram Iyer, M.Sc Mathematics · Updated Jun 2026 · 1 min read

This discriminant reference table shows the discriminant (b² − 4ac) for a range of a values, assuming a b of 5 and a c of 6. Every figure is computed with the same engine that powers our Discriminant Calculator, so the numbers are exact.

aDiscriminant (b² − 4ac)
0.2519.0000
0.513.0000
0.757.0000
11.0000
1.5-11.0000
2-23.0000
3-47.0000
5-95.0000
7-143.0000
10-215.0000

How to use this table

Find the row closest to your a and read across to the discriminant (b² − 4ac). For a value between two rows, the real figure sits between them — or enter your exact numbers in the Discriminant Calculator for a precise answer.

Need a value that is not in the table? — the Discriminant Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring math calculators with these tools: Margin of Error Calculator, Sample Size Calculator, Confidence Interval Calculator, Coefficient of Variation Calculator, Regular Heptagon Area Calculator.

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Frequently asked questions

Each cell is computed with the standard formula using exact arithmetic — the same calculation behind our Discriminant Calculator — so every figure is accurate for the stated assumptions.

Yes. The table covers common a values; for any exact figure, enter your own numbers in the Discriminant Calculator.

Vikram Iyer · M.Sc Mathematics

Vikram Iyer is a mathematics educator with over fifteen years of teaching experience, specialising in making quantitative concepts clear and practical for everyday use.