Quadratic Formula Calculator

Solve quadratic equations, find roots, discriminant, vertex, axis of symmetry, and graph details with this free quadratic formula calculator.

Calculate Quadratic Formula

x = (-b ± √(b² - 4ac)) / 2a
Your result will appear here.

How the quadratic formula works

Standard form:
ax² + bx + c = 0

Quadratic formula:
x = (-b ± √(b² - 4ac)) ÷ 2a

Discriminant:
D = b² - 4ac

Vertex:
x = -b ÷ 2a, then substitute into the equation

Why quadratic equations matter

Quadratic equations appear in algebra, geometry, physics, engineering, business, and anywhere curved relationships or parabolic motion are involved.

They help describe projectile paths, area problems, optimization, and many real-world models.

What your result means

Your result shows the roots of the quadratic equation along with the discriminant, vertex, axis of symmetry, y-intercept, and line behavior.

This helps you understand whether the parabola crosses the x-axis, where it turns, and how it is positioned on the graph.

Quadratic calculator tips

Frequently asked questions

What is the quadratic formula?

The quadratic formula is x = (-b ± √(b² - 4ac)) ÷ 2a.

What does the discriminant tell you?

It tells you whether the equation has two real roots, one real root, or two complex roots.

What is the vertex of a parabola?

The vertex is the turning point where the parabola reaches its maximum or minimum value.

What happens if a = 0?

The equation becomes linear, not quadratic.