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Quadratic Equation Calculator

Your inputs

ax² + bx + c = 0; roots use the discriminant b² − 4ac.

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Result visualization

Find real or complex roots and explore a parabola — the roots and the vertex are marked on the graph, the discriminant verdict is spelled out in words, and the factorised form is shown whenever the roots are tidy numbers.

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UNDERSTAND YOUR RESULTS

Quadratic Equation Calculator guide

Find real or complex roots and explore a parabola — the roots and the vertex are marked on the graph, the discriminant verdict is spelled out in words, and the factorised form is shown whenever the roots are tidy numbers.

How to use this tool

  1. Enter Coefficient a, Coefficient b, Coefficient c.
  2. Change a value to update the results and illustration. Check any validation message before using the output.
  3. Copy the results or download CSV. Reset restores the example values.

A worked example

For x² − 3x + 2 = 0, the roots are 1 and 2 and the discriminant is 1, so the equation factorises as (x − 1)(x − 2) = 0; both roots and the vertex at (1.5, −0.25) are marked on the graph. For x² + 1 = 0 the discriminant is −4, so there are no real roots — only the complex pair i and −i.

What you can do with this tool

How it works

ax² + bx + c = 0; roots use the discriminant b² − 4ac.

Frequently asked questions

How should I interpret the illustration?

It is a visual aid, not a replacement for the numeric output. Some charts compare values with different units, and those magnitudes are not directly comparable.

Can I use the result without checking the inputs?

Check units, signs, assumptions and rounding first. The tool cannot know whether the values you enter describe the real situation correctly.