The Discriminant

The Discriminant

What is the Discriminant??

This is part of the quadratic formula that informs us how how many solutions the quadratic equation will have.

Why is it Important??

When solving using the quadratic formula, you will know how many solutions you should have.

-a positive answer = 2 real roots

-a zero answer = 1 real root

-a negative answer = no real roots

Finding the Discriminant

1. Your equation must be in standard form.
2. Identify the a, b, and c from the equation.
3. Plug the values into  $b^2-4ac$  and then solve!!

 $y\ =x^2-8x+16$  

Find the discriminant:

1. The a = __   b = __  c = __
2. Plug into:  $b^2-4ac$  



3. So how many solutions does the equation have?

Multiple Choice

If the discriminant is positive, then the solution will be

• One real solution

• two real solutions

• two non-real solutions

• all real numbers

Multiple Choice

If the discriminant is negative, then the solution will be

• one real solution

• two real solutions

• two non-real solutions

• all real numbers

Multiple Choice

Determine the value of the discriminant

 $y=x^2+7x+13$  

• 101

• 3

• -101

• -3

Multiple Choice

Describe the number and type solutions for the following:

 $y=x^2+7x+13$  

• 2 real solutions

• 2 non-real solutions

• 1 real solution

• 1 non-real solution

Multiple Choice

For the function below, what is the discriminant?

 $x^2+8x+16=0$  

• 4

• -4

• 0

• 2