Quadratic Formula Calculator

Solve any quadratic equation instantly with our easy-to-use calculator. Get step-by-step solutions and understand the quadratic formula in depth.

Quadratic Equation Solver

Enter coefficients for ax² + bx + c = 0

Solution

What is the Quadratic Formula?

Understanding the foundation of quadratic equations

Quadratic Equations

A quadratic equation is a second-degree polynomial equation in a single variable x, with a ≠ 0. The standard form of a quadratic equation is:

ax² + bx + c = 0

Where:

  • a is the coefficient of x² (quadratic coefficient)
  • b is the coefficient of x (linear coefficient)
  • c is the constant term

The Quadratic Formula

The quadratic formula provides the solution(s) to any quadratic equation. It is derived from completing the square of the standard quadratic equation:

x = [-b ± √(b² - 4ac)] / 2a

The expression under the square root, b² - 4ac, is called the discriminant. It determines the nature of the roots:

  • Positive discriminant: Two distinct real roots
  • Zero discriminant: One real root (repeated)
  • Negative discriminant: Two complex roots

How to Use the Quadratic Formula

Step-by-step guide to solving quadratic equations

Step-by-Step Process

  1. Identify the coefficients

    From your quadratic equation in the form ax² + bx + c = 0, identify the values of a, b, and c.

  2. Calculate the discriminant

    Compute the value of the discriminant using the formula: D = b² - 4ac

  3. Determine the nature of roots

    Based on the discriminant value:

    • If D > 0: Two distinct real roots
    • If D = 0: One real root (repeated)
    • If D < 0: Two complex roots

  4. Apply the quadratic formula

    Substitute the values of a, b, and the discriminant into the quadratic formula:

    x = [-b ± √D] / 2a

  5. Simplify the results

    Calculate the two possible values of x by using both the plus and minus signs in the formula.

Why Use Our Quadratic Calculator?

Experience the best quadratic equation solver with these features

Instant Results

Get immediate solutions to any quadratic equation with our optimized calculation engine.

Step-by-Step Solutions

Understand the process with detailed step-by-step explanations for each calculation.

Privacy Focused

All calculations happen locally in your browser. We never store or transmit your data.

Handles All Cases

Works with real and complex roots, providing accurate solutions for any quadratic equation.

Fully Responsive

Use our calculator on any device - desktop, tablet, or mobile - with perfect experience.

Educational Value

Learn the quadratic formula and how to apply it with our comprehensive explanations.

Frequently Asked Questions

Find answers to common questions about quadratic equations

What is a quadratic equation?

A quadratic equation is a second-degree polynomial equation in a single variable x, with the general form ax² + bx + c = 0, where a, b, and c are constants and a ≠ 0.

What is the quadratic formula?

The quadratic formula is x = [-b ± √(b² - 4ac)] / 2a. It provides the solution(s) to any quadratic equation of the form ax² + bx + c = 0.

What does the discriminant tell us?

The discriminant (b² - 4ac) determines the nature of the roots:

  • If discriminant > 0: Two distinct real roots
  • If discriminant = 0: One real root (repeated)
  • If discriminant < 0: Two complex roots

Can a quadratic equation have only one solution?

Yes, when the discriminant equals zero, the quadratic equation has exactly one real solution (a repeated root).

What if I get a negative number under the square root?

If the discriminant is negative, the quadratic equation has two complex roots. Our calculator will display these complex solutions using the imaginary unit i (where i² = -1).

Can I use this calculator for my homework?

Absolutely! Our quadratic formula calculator is perfect for students to check their work, understand the solving process, and learn how to apply the quadratic formula correctly.

Ready to Solve Quadratic Equations?

Try our quadratic formula calculator now and get instant solutions with detailed explanations