1. Solving Quadratic Equations by the Quadratic Formula

2. THE QUADRATIC FORMULA
When you solve using completing the square on the general formula you get:
This is the quadratic formula!
Just identify a, b, and c then substitute into the formula.

3. WHY USE THE QUADRATIC FORMULA?
The quadratic formula allows you to solve ANY quadratic equation, even if you cannot factor it.
An important piece of the quadratic formula is what’s under the radical:
b2 – 4ac
This piece is called the discriminant.

4. Example #1 a=2, b=7, c=-11 Discriminant = Discriminant =
Find the value of the discriminant and describe the nature of the roots (real,imaginary, rational, irrational) of each quadratic equation. Then solve the equation using the quadratic formula) 1.
a=2, b=7, c=-11
Discriminant =
Value of discriminant=137
Positive-NON perfect square
Nature of the Roots – 2 Reals - Irrational
Discriminant =

5. Example #1- continued
Solve using the Quadratic Formula

6. Quadratic Formula
There once a negative boy who was all mixed up so he went to this radical party. Because the boy was square, he lost out on
4 awesome chicks so he cried his way home
when it was all over at 2 AM.

7. Solving Quadratic Equations by the Quadratic Formula
Try the following examples. Do your work on your paper and then check your answers.