Quadratic Equation Solver

Solve any quadratic equation and find its roots.

Root x₁

2

Root x₂

1

Discriminant (Δ)

1

Value Breakdown

Properties Comparison

Properties Comparison

PropertyFormulaValue
Root x₁(−b + √Δ) / 2a2
Root x₂(−b − √Δ) / 2a1
Discriminant (Δ)b² − 4ac1
Vertex Yf(−b / 2a)(1.5, -0.25)

Understanding Quadratic Equation

The quadratic equation solver finds the roots of any quadratic equation of the form ax squared plus bx plus c equals zero, providing both real and complex solutions with step-by-step explanations. Quadratic equations appear throughout mathematics, physics, engineering, economics, and many other fields, making this one of the most practically useful calculators available. The calculator uses the quadratic formula, which computes the solutions as negative b plus or minus the square root of b squared minus four times a times c, all divided by two times a. The expression under the square root, called the discriminant, determines the nature of the solutions. A positive discriminant yields two distinct real roots, zero gives exactly one repeated real root, and a negative discriminant produces two complex conjugate roots. The calculator identifies which case applies to your equation and presents the results accordingly. Beyond just giving the answer, this tool shows the complete solution process so you can learn and verify each step. It also displays the vertex of the parabola represented by the equation, the axis of symmetry, and whether the parabola opens upward or downward. Use this free quadratic equation solver for algebra homework, physics problems involving projectile motion, optimization problems, or any application requiring the roots of a quadratic function.

Practical Example

x = (−b ± √(b² − 4ac)) / 2a. Discriminant Δ = b² − 4ac. If Δ > 0: two real roots. If Δ = 0: one repeated root. If Δ < 0: no real roots.

Frequently Asked Questions

What is the quadratic formula?

For ax² + bx + c = 0, the solutions are x = (−b ± √(b² − 4ac)) / (2a).

What does the discriminant tell me?

The discriminant b² − 4ac shows the nature of roots: positive = two real, zero = one repeated, negative = two complex roots.

Are complex roots real solutions?

Complex roots aren't real numbers but are valid mathematical solutions and appear in many physics and engineering problems.

What if I get a different answer when calculating manually?

First check your order of operations (PEMDAS/BODMAS), then verify your units are consistent. Common errors include rounding too early, sign mistakes, and incorrect formula application. Use this calculator to verify each step of your work.

Are there shortcuts or mental math tricks?

Yes! Many mathematical operations have estimation shortcuts. For example, squaring numbers ending in 5, using the distributive property, or applying benchmark fractions. While shortcuts help with estimates, always use exact calculations for important work.

Disclaimer: This calculator provides estimates for informational purposes only. Actual results may vary. Consult a qualified professional for personalized advice.

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