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Quadratic Equation calculator

Solve ax² + bx + c = 0 and see the roots, the vertex of the parabola and the discriminant.

How it works Report a problem

Quadratic Equation calculator

Enter your values below and press Calculate to see your result instantly.

x² + x + = 0
The Roots (x₁, x₂)
x = 3, x = 2
THE VERTEX (Min/Max)
(2.5, -0.25)
THE DISCRIMINANT (Δ)
1
The discriminant is positive, meaning the parabola intersects the x-axis at two distinct real points.

About the Quadratic Equation calculator

Solve ax² + bx + c = 0 and see the roots, the vertex of the parabola and the discriminant.

How to use the Quadratic Equation calculator

  1. Enter the coefficients in the equation ax² + bx + c = 0.
  2. Press Solve Equation to see the roots, the vertex and the discriminant.

Formula and method

x = (−b ± √(b² − 4ac)) ÷ 2a. The vertex is at x = −b ÷ 2a.

Worked example

x² − 5x + 6 = 0 has the roots x = 3 and x = 2, with the vertex at (2.5, −0.25).

Tips

  • The discriminant b² − 4ac decides the number of real roots.
  • If a is zero the equation is linear, not quadratic.

Frequently asked questions

What does the vertex represent?
The lowest point of a parabola that opens upward, or the highest point of one that opens downward.