Quadratic equation solver
Solve quadratic equations with the quadratic formula, step by step, and see the graph.
How to useax² + bx + c = 0
x² + x + = 0
–
Available in: 
Advertisement
Quadratic equation solver: what it is for
The calculator solves any quadratic equation (ax² + bx + c = 0) with the quadratic formula and shows the working: discriminant, roots, sum and product and the vertex.
It also draws the parabola with the roots marked and shows the complex roots when the discriminant is negative.
How to use
- Type the values of a, b and c.
- See the discriminant and the roots.
- Check the step by step and the graph.
When to use it
- Checking math homework.
- Studying for tests and exams.
- Understanding the parabola graph.
Frequently asked questions
What if the discriminant is negative?
The equation has no real roots. The calculator shows the complex roots, with the imaginary part i.
What is the vertex?
It is the lowest point (if a > 0) or highest point (if a < 0) of the parabola. Its coordinates are xv = −b/2a and yv = −Δ/4a.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.