There is also a formula that can be used to solve cubic equations, where you see a term with x to the 3rd power. However, the formula is quite complex, so it's more common to solve cubic equations using other methods.

When the discriminant in the quadratic formula comes out to 

, there is only one real solution to the quadratic equation. This video explains how and why.

When you work with quadratic equations, the discriminant is what is under the square root when you use the quadratic formula

An equation that can be written in the form 

where the coefficient a is not equal to 0

The number in front of a variable or product of variables, showing how many you have of that variable or product of variables

Mathagon

Definition

Using the Quadratic Formula

Solving Unorganized Equations

Positive Discriminant

Discriminant Is 0

Negative Discriminant

Coefficient b is 0

Coefficient c Equals 0

Quadratic Equations

When the discriminant in the quadratic formula comes out to 0, there is only one real solution to the quadratic equation. This video explains how and why. 

What Happens When The Discriminant is 0?