Quadratic Equation Calculator

Solve quadratic equations of the form ax² + bx + c = 0 using the quadratic formula.

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Updated January 2025
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Quadratic Equation Calculator

ax² + bx + c = 0

ax² + bx + c = 0

Quadratic Equations

A quadratic equation is a second-degree polynomial equation of the form ax² + bx + c = 0. The solutions, or 'roots', are found using the quadratic formula: x = [-b ± √(b²-4ac)] / 2a. The graph of a quadratic equation is a parabola.

How the Quadratic Equation Calculator Works

A quadratic equation is a polynomial equation of degree 2, written in the standard form ax² + bx + c = 0, where a ≠ 0. These equations produce parabolic curves when graphed and have wide applications in physics, engineering, and economics.

Key Properties

  • Standard Form: ax² + bx + c = 0
  • Solutions: Can have 2, 1, or 0 real solutions (roots)
  • Graph: Always forms a parabola (U-shaped curve)

Solving Methods

Quadratic Formula

x = (-b ± √(b² - 4ac)) / (2a)

The most reliable method that works for all quadratic equations. The discriminant (b² - 4ac) determines the number of real solutions.

The Discriminant

  • If b² - 4ac > 0: Two distinct real solutions
  • If b² - 4ac = 0: One repeated real solution
  • If b² - 4ac < 0: No real solutions (complex solutions)

Factoring Method

When possible, factor the equation into (x - r₁)(x - r₂) = 0

Example: x² - 5x + 6 = 0 → (x - 2)(x - 3) = 0 → x = 2 or x = 3

Completing the Square

Convert to the form (x - h)² = k and solve for x

Steps:

  1. Move constant to right side
  2. Complete the square on left side
  3. Take square root of both sides
  4. Solve for x

Real-World Applications

Projectile Motion

Calculate the trajectory of objects thrown or launched, finding maximum height and landing distance.

Business & Economics

Find profit maximization points, break-even analysis, and optimal pricing strategies.

Engineering

Design bridges, arches, and structures; analyze stress and load distributions.

Area Problems

Calculate dimensions for maximum area with given perimeter constraints in construction and landscaping.

Frequently Asked Questions