Quadratic Equation Solver

Solve quadratic equations in the form ax² + bx + c = 0. This calculator provides both real and complex solutions.

Quadratic Equation Solver – Instantly Solve Any Quadratic Equation

The Quadratic Equation Solver is a powerful online tool designed to quickly and accurately solve any quadratic equation in the form ax² + bx + c = 0. Whether you're a student, engineer, or anyone dealing with algebra, this solver provides step-by-step results including real and complex roots.

What is a Quadratic Equation?

A quadratic equation is a second-degree polynomial equation involving the variable x. It is written in the standard form:

ax² + bx + c = 0

Quadratic Formula

The most common method for solving a quadratic equation is the quadratic formula:

x = [-b ± √(b² - 4ac)] / (2a)

This formula gives the roots (solutions) of the quadratic equation. The part under the square root, b² - 4ac, is called the discriminant.

How to Use the Quadratic Equation Solver

  1. Enter the values of a, b, and c from your equation.
  2. Click the "Solve" button.
  3. View the result with both roots (real or complex).

Example 1 – Two Real Roots

Equation: x² - 5x + 6 = 0

Example 2 – One Real Root

Equation: x² - 4x + 4 = 0

Example 3 – Complex Roots

Equation: x² + 2x + 5 = 0

Understanding the Discriminant

The discriminant (D = b² - 4ac) helps determine the nature of the roots:

Methods to Solve Quadratic Equations

Applications of Quadratic Equations

Graphical Representation

The graph of a quadratic equation is a parabola. It opens upward if a > 0 and downward if a < 0. The x-intercepts represent the real roots, and the vertex is the minimum or maximum point.

Vertex Formula

Vertex (h, k):

h = -b / 2a
k = f(h)

The vertex provides useful insight into optimization problems.

Tip: Always Check for Factorization

If the quadratic equation can be factored easily, you can solve it faster without using the formula. For example:

x² + 5x + 6 = 0 → (x + 2)(x + 3) = 0 → x = -2, -3

Handling Decimal and Fractional Coefficients

The solver supports decimal and fractional inputs for a, b, and c. Make sure to enter values carefully, especially when using parentheses or negative signs.

Frequently Asked Questions

Can the equation have no real solution?

Yes, if the discriminant is negative, the roots will be complex numbers (i.e., involve the imaginary unit i).

Can I use the solver for equations with decimals?

Yes, you can enter any real number including decimals or fractions.

Does this work on mobile?

Absolutely. The tool is mobile-optimized and works seamlessly across devices.

Is it suitable for school or university work?

Yes, this calculator is designed to help with academic algebra, homework, and competitive exams.

Programming the Quadratic Formula (Python)


import cmath

def solve_quadratic(a, b, c):
    d = cmath.sqrt(b**2 - 4*a*c)
    x1 = (-b + d)/(2*a)
    x2 = (-b - d)/(2*a)
    return x1, x2
  

The Meta Description

Free Quadratic Equation Solver to find roots of any equation in the form ax² + bx + c = 0. Supports real and complex solutions. Fast, accurate, and easy to use.

The Keywords

quadratic equation solver, solve ax² + bx + c = 0, online quadratic solver, quadratic formula calculator, find complex roots, math algebra calculator, parabola root finder

Final analysis

The Quadratic Equation Solver offers a fast, convenient, and reliable way to solve quadratic equations. With support for both real and imaginary solutions, it’s ideal for algebra students, teachers, and professionals alike. Whether you're solving problems by hand or checking answers, this calculator ensures accuracy every time.

Real-World Applications of Quadratic Equations

Quadratic equations aren't just confined to the classroom—they’re everywhere in real life. Understanding how to apply them gives you a strong edge in various careers and scenarios.

1. Projectile Motion

In physics, quadratic equations describe the path of any object thrown in the air, forming a parabolic trajectory. For example, the equation h(t) = -16t² + vt + s models vertical motion where:

Solving this quadratic helps find when an object hits the ground or reaches maximum height.

2. Business and Economics

Businesses often use quadratic equations in profit modeling. For instance, if revenue and costs are expressed as functions of output, the break-even point can be found by solving a quadratic:

Profit = Revenue - Cost = ax² + bx + c

3. Engineering and Architecture

Engineers use quadratic functions to calculate load distributions, beam strengths, and cable tensions. Architects use parabolic arches in bridges and buildings, which require quadratic solutions for structural balance.

4. Computer Graphics

Quadratic Bezier curves are used in vector-based graphic software and font design. Solving quadratic equations allows precise drawing and animation.

5. Agriculture and Optimization

Farmers may use quadratic models to maximize crop yield based on area and cost constraints. Solving for the vertex helps determine the best input values.

When to Use This Calculator

Benefits of Quadratic Calculators Over Manual Solving

How to Check if an Equation is Quadratic

An equation is quadratic if:

Example: 2x² - 3x + 7 = 0 → quadratic
x - 4 = 0 → not quadratic (linear)

Solving Quadratic Equations Graphically

If you plot y = ax² + bx + c on a coordinate system, the x-values where the graph intersects the x-axis are the roots of the equation. These points are the solutions to ax² + bx + c = 0.

Alternative Forms of Quadratic Equations

Besides the standard form, quadratics can be expressed in other forms:

1. Vertex Form:

y = a(x - h)² + k
Easier to find the vertex (h, k) of the parabola

2. Factored Form:

y = a(x - r₁)(x - r₂)
Makes it easy to identify roots r₁ and r₂

Completing the Square – Manual Method

If you need to solve a quadratic without a calculator, completing the square is a helpful technique:

Example: x² + 6x + 5 = 0

  1. Move constant: x² + 6x = -5
  2. Add (6/2)² = 9: x² + 6x + 9 = 4
  3. Factor: (x + 3)² = 4
  4. Solve: x + 3 = ±2 → x = -1 or -5

Interactive Learning: Use With Graphing Tools

Pair this solver with a graphing calculator to visualize how coefficients affect the shape and roots of the parabola. Change values of a, b, and c to see shifts, stretches, and flips in real-time.

Helpful Tip: Decoding Your Results

Common Mistakes to Avoid

Use Cases for Teachers and Tutors

Quadratic Word Problem Examples

1. Area Problem: A rectangle has an area of 60 m². Its length is (x + 5) and width is (x - 3). Find x.

Solution: (x + 5)(x - 3) = 60 → x² + 2x - 15 = 60 → x² + 2x - 75 = 0

Use the calculator to solve x² + 2x - 75 = 0

2. Falling Object: A ball is thrown upward with a velocity of 20 m/s. Its height in meters is modeled by h(t) = -5t² + 20t. When does the ball reach the ground?

Solve: -5t² + 20t = 0 → t(-5t + 20) = 0 → t = 0 or 4 seconds

Practice Exercises

Final analysis

Whether you're analyzing motion, modeling profits, or solving complex math problems, the Quadratic Equation Solver provides everything you need to solve with confidence. It’s fast, accurate, and perfect for algebra students and professionals alike. Try different values to explore how quadratics behave and enhance your problem-solving skills today.

See Also