Toolverge

Quadratic Equation Solver

A quadratic equation has the form ax² + bx + c = 0, where a is non-zero. Toolverge solves it with the quadratic formula, first computing the discriminant (b² − 4ac) to determine whether the roots are two real numbers, one repeated real number, or a complex conjugate pair, then reports the vertex and axis of symmetry of the parabola y = ax² + bx + c.

Discriminant

1

x1 = 2, x2 = 1

Vertex: (1.5, -0.25); axis of symmetry x = 1.5

How it works

  1. Enter coefficients a, b, and c.
  2. The discriminant b²−4ac determines real, repeated, or complex roots.
  3. The vertex and axis of symmetry are computed from the same coefficients.

Formula x = (−b ± √(b²−4ac)) / 2a; vertex x = −b/2a

Frequently asked questions

How do I solve x²−3x+2=0?

Using the quadratic formula with a=1, b=−3, c=2 gives roots x=1 and x=2.

What does a negative discriminant mean?

It means the equation has no real roots — the two roots are a complex conjugate pair.

What is the vertex of a parabola?

The point where the parabola turns; its x-coordinate is −b/2a, also called the axis of symmetry.

Can a be zero?

No. If a=0 the equation is linear, not quadratic, so a must be non-zero.

What does a discriminant of zero mean?

The equation has exactly one repeated real root, and the vertex touches the x-axis there.