x =-b ± √(b² - 4ac)2a

Solve quadratic equations in the form ax² + bx + c = 0 to find real and complex roots completely instantly.

x²  +x  += 0

The Comprehensive Guide to Quadratic Formula Calculator

What is a Quadratic Formula Calculator?

A Quadratic Formula Calculator is a specialized algebraic tool designed to solve second-degree polynomial equations of the form ax² + bx + c = 0.

By inputting the coefficients (a, b, and c), the calculator instantly applies the quadratic equation to determine the exact roots (x-intercepts) of the parabola. It intelligently detects and calculates both real roots and complex (imaginary) roots.

Related Terms: Quadratic Formula Calculator

The Mathematical Formula

x = [-b ± √(b² - 4ac)] / 2a

Solving for roots of ax² + bx + c = 0.

Calculation Example

Let's solve the equation: 2x² - 4x - 6 = 0

  • Here, a = 2, b = -4, and c = -6.
  • Calculate Discriminant: (-4)² - 4(2)(-6) = 16 + 48 = 64
  • x = [ -(-4) ± √64 ] / 2(2)
  • x = [ 4 ± 8 ] / 4
  • Root 1: (4 + 8) / 4 = 12 / 4 = 3
  • Root 2: (4 - 8) / 4 = -4 / 4 = -1

The roots are x = 3 and x = -1.

Strategic Use Cases

  • Algebra & Calculus Homework: Instantly check answers to complex quadratic equations without manual calculation.
  • Physics Calculations: Highly useful in kinematics to calculate exactly when a projectile will hit the ground (where height = 0).
  • Engineering Optimization: Finding maximum or minimum values (optimization) in systems described by parabolic curves.

Frequently Asked Questions

What happens if variable 'a' is zero?

If 'a' is zero, the equation is no longer quadratic; it becomes a linear equation (bx + c = 0). Our calculator will detect this and solve the linear equation for you (x = -c/b).

Why do some equations output an 'i'?

The 'i' represents an imaginary number (the square root of -1). This occurs when the discriminant (b² - 4ac) is negative. Because you cannot take the square root of a negative number in real mathematics, the result consists of two complex conjugate roots.

How accurate is this calculator?

Our calculator uses industry-standard formulas to provide the most accurate results possible. However, it should be used for informational purposes only and not as a basis for formal calculations or legal advice.

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