Quadratic Equation Calculator

Find the roots of a quadratic equation in the form ax² + bx + c = 0. Visualize the graph and calculate the vertex, discriminant, and solutions.

Enter Quadratic Equation

x²+3x-4 = 0

The Quadratic Formula

For a quadratic equation ax² + bx + c = 0:

x = (-b ± √(b² - 4ac)) / (2a)

The term b² - 4ac is called the discriminant (Δ):

  • If Δ > 0: Two distinct real solutions
  • If Δ = 0: One real solution (repeated root)
  • If Δ < 0: Two complex conjugate solutions

Quadratic Function Analysis

Graph of x²+3x-4 = 0

Solutions

Calculate to see the solutions.

Properties

Calculate to see function properties.

Common Quadratic Equations

x² - 4 = 0

Roots: x = ±2

x² - 2x - 3 = 0

Roots: x = 3, x = -1

2x² + x - 6 = 0

Roots: x = 2, x = -3/2

x² + 4x + 4 = 0

Root: x = -2 (double root)

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Frequently Asked Questions

Find answers to common questions about Online Calculator.

A Quadratic Equation Calculator is an online tool that helps solve quadratic equations of the form ax² + bx + c = 0 by finding the roots using the quadratic formula.

The calculator uses the quadratic formula: x = (-b ± √(b² - 4ac)) / 2a. It calculates the discriminant (b² - 4ac) to determine the nature of the roots.

The discriminant Δ = b² - 4ac determines the type of roots:

  • If Δ > 0, there are two distinct real roots.
  • If Δ = 0, there is one repeated real root.
  • If Δ < 0, the roots are complex (imaginary).

Yes, the calculator supports both decimal and fraction values for a, b, and c.

If a = 0, the equation is not quadratic but linear (bx + c = 0). The calculator will either solve it as a linear equation or show an error.

Yes, if the discriminant is negative, the calculator provides complex roots in the form x = p ± qi.

Yes! Quadratic equations are widely used in physics (e.g., projectile motion), engineering, and economics, making this tool useful in multiple fields.

Some versions of the calculator include step-by-step explanations for solving quadratic equations, including calculations for the discriminant and roots.

By default, the calculator provides results with a certain decimal precision. Some versions allow users to customize the decimal places.

If you enter non-numeric values, the calculator will display an error or prompt you to enter valid numbers.

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