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Quadratic Equation Calculator : Solve ax² + bx + c = 0 with Discriminant

The Quadratic Equation Calculator finds the roots of second-degree polynomial equations ax² + bx + c = 0. It calculates the discriminant (Δ = b² - 4ac), identifies vertex coordinates, and outputs exact real or complex roots.

Interactive Calculator

100% Client-Side Engine
Quadratic Form: ax² + bx + c = 0
x²
+
x
+= 0
Quadratic Roots (two_real)
x₁ = 3, x₂ = 2
Discriminant (D = b² - 4ac)
1
Parabola Vertex (h, k)
(2.5, -0.25)
Parabola Orientation
Opens upward
Quadratic Formula Derivation
1. Standard Form: 1x² + -5x + 6 = 0
2. Discriminant: D = b² - 4ac = (-5)² - 4(1)(6) = 1
3. D > 0: Two distinct real roots:
x₁ = (-b + √D) / 2a = (5 + 1) / 2 = 3
x₂ = (-b - √D) / 2a = (5 - 1) / 2 = 2
4. Vertex: (2.5, -0.25)

Step-by-Step Examples

Solving x² - 5x + 6 = 0

Factoring quadratic with two distinct real roots.

Inputs: a: 1, b: -5, c: 6
Result: x₁ = 3, x₂ = 2 (Δ = 1 > 0)

Δ = (-5)² - 4(1)(6) = 25 - 24 = 1. Roots are (5 ± 1)/2 = 3 and 2.

How to Use This Tool

  1. Enter coefficient a (quadratic term).
  2. Enter coefficient b (linear term) and constant c.
  3. Click Calculate to see the discriminant, nature of roots, vertex (h, k), and exact roots.

Frequently Asked Questions

When Δ < 0, the equation has no real roots and instead produces two complex conjugate solutions with imaginary component i = √(-1).