Quadratic Equation Solver

Roots, discriminant and vertex for any ax² + bx + c = 0.

Two real roots
x = 4, -1
Discriminant
25
Vertex
(1.5, -6.25)
Sum of roots
3
Product of roots
-4
Show the working
  1. 1Discriminant = b² − 4ac = 25 (> 0, two real roots)
  2. 2x = (−-3 ± √25) ÷ 2
Formula
x = (−b ± √(b² − 4ac)) ÷ 2a

How it works

Solves any quadratic ax² + bx + c = 0, reporting real or complex roots plus the vertex and discriminant.

Example

x² − 3x − 4 = 0 has roots x = 4 and x = −1.

About the Quadratic Equation Solver

Roots, discriminant and vertex for any ax² + bx + c = 0. It sits in the Math & Algebra section of NWS Calc, a free collection of calculators that run entirely in your browser. There is no signup, no paywall and no tracking — open the page, enter your numbers, get an answer.

Frequently asked questions

Is the Quadratic Equation Solver free to use?
Yes. Every calculator on NWS Calc is completely free, with no signup, no usage limits and no ads.
Does my data leave my device?
No. The Quadratic Equation Solver runs entirely in your browser using JavaScript. Nothing you type is uploaded, logged or stored on a server.
Can I use the Quadratic Equation Solver on my phone?
Yes. The page is fully responsive and works in any modern mobile or desktop browser — there is nothing to install.
What else is in Math & Algebra?
Equations, fractions, primes, roots, sequences and number theory. You can browse the full Math & Algebra category for related calculators.

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