Quadratic Equation Calculator

Author: Henrick Yau
- 12 October 2026
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Calculators

Solve quadratic equations in the form ax² + bx + c = 0. Enter the coefficients a, b, and c to find the roots, discriminant, vertex, and graph the parabola.

Equation Coefficients

1x² + 0x + 0 = 0
Cannot be zero for quadratic equation
Linear term coefficient
Constant term

Display Options

Understanding Quadratic Equations

A quadratic equation is a polynomial equation of degree 2 in the form ax² + bx + c = 0, where a ≠ 0. These equations describe parabolic curves and have many real-world applications.

Key Concepts
  • Discriminant (Δ): b² - 4ac determines the nature of roots
  • Vertex: The highest or lowest point of the parabola at (-b/2a, f(-b/2a))
  • Axis of Symmetry: Vertical line x = -b/2a that divides the parabola
  • Roots/Zeros: x-values where the parabola crosses the x-axis
  • Y-intercept: Point where parabola crosses y-axis at (0, c)
Solution Methods
  • Quadratic Formula: x = (-b ± √(b² - 4ac)) / 2a
  • Factoring: Express as (px + q)(rx + s) = 0
  • Completing the Square: Rewrite as (x + h)² = k
  • Graphing: Find x-intercepts of the parabola
Types of Solutions
  • Two Real Roots: Δ > 0, parabola crosses x-axis twice
  • One Real Root: Δ = 0, parabola touches x-axis (perfect square)
  • Complex Roots: Δ < 0, parabola doesn't cross x-axis

Note: This calculator provides exact and approximate solutions for quadratic equations. For educational purposes, review the solution steps to understand the mathematical process. Complex solutions are displayed in a + bi form.

Solving ax² + bx + c = 0

The Quadratic Equation Calculator is a useful tool for solving equations in the standard form ax² + bx + c = 0. It lets you enter the coefficients (a, b, and c) to find solutions quickly and accurately. This calculator supports several solving methods and visualisations, making it ideal for students, teachers, and anyone exploring quadratic functions.

Quadratic Formula:
x = (-b ± √(b² - 4ac)) / 2a

Benefits of using this quadratic solver

This calculator helps you:

  • Solve quadratic equations using different methods like the quadratic formula, factorising, or completing the square.
  • Visualise solutions with a clear graph of the parabola.
  • Understand each step with a detailed explanation of the solution process.
  • Analyse equation properties such as roots, vertex, axis of symmetry, and discriminant.

Whether you're tackling homework or revising concepts, this quadratic formula solver acts as a reliable maths problem solver and educational tool.

Enter coefficients and choose a method

Follow these simple steps to find your solution:

  • Enter values for coefficients a, b, and c.
  • Select a solution method: Quadratic Formula, Factorising, or Completing the Square.
  • Choose whether to show solution steps and the graph.
  • Adjust decimal precision and graph range if needed.
  • Click Solve Equation to see the results.

Roots, discriminant, vertex and graph

The results include:

  • Roots: The x-values where the equation equals zero (real or complex).
  • Discriminant: Indicates the nature of the roots.
  • Vertex: The turning point of the parabola.
  • Graph: A visual display of the parabola, including key features.
  • Equation Properties: Domain, range, intercepts, and symmetry line.

Educational Support with Step-by-Step Solutions

Learning how to solve quadratic equations is easier when you can see each stage clearly. This tool breaks down every part of the solution, acting as a maths solver tool and quadratic formula solution guide. It is especially useful for those studying algebra or preparing for exams.

Questions about solving quadratic equations

  • Can this tool solve all quadratic equations?
    Yes, as long as coefficient a ≠ 0, it can solve any quadratic equation, including those with complex roots.
  • Does it show all solution steps?
    Yes, you can choose to display the full step-by-step breakdown of the selected solving method.
  • Can I graph the equation?
    Yes. Enable the graph option to see a detailed plot of the parabola with labelled features.
  • What if the equation can’t be factorised?
    If factorising is not possible, the calculator automatically switches to the quadratic formula.

More Helpful Maths Tools

This calculator complements many other tools that support learning and solving equations:

Understanding quadratics with this tool

The Quadratic Equation Calculator is more than a formula tool—it is a practical resource for understanding, solving, and visualising quadratic equations. Whether you are learning how to find roots of quadratic functions or just need a quick answer, this quadratic formula calculator is a dependable helper.