$$ax^2 + bx + c = 0$$

## How To Use the Quadratic Formula Calculator

This online calculator will solve a quadratic equation (of the form ax2 + bx + c = 0) using the quadratic formula. All you have to do is enter in a, b, c (which are the coefficients in the equation).

The output will be the real / complex roots that solve the equation. As a refresher, here is how many roots one should expect based on the values of a, b, and c.

• When b2−4ac=0 there is one real root.

• When b2−4ac>0 there are two real roots.

• When b2−4ac<0 there are two complex roots.

Important Considerations

• The polynomial must be second-order, such as ax2 + bx + c = 0

• a ≠ 0

## What is the Quadratic Formula?

 = constants, where a ≠ 0 = the unknown