Download 9.8 The Quadratic Formula

9.8 The Quadratic Formula
Algebra 19.0, 20.0
Main Idea
• Today, we are going to learn the final method
to solving quadratic equations: THE
QUADRATIC FORMULA.
• The Quadratic Formula works EVERYTIME.
The Quadratic Formula
• THE QUADRATIC FORMULA:
 b  b  4ac
x
2a
2
1)
2)
3)
4)
Write the problem in standard form
Identify a, b, c
Plug the values into the formula
Solve using PEMDAS
Ex 1- Using the Quadratic Formula
Practice 1
Ex 2-Use Quadratic Formula to
Estimate Solutions
• We can get irrational solutions, so leave them
as complex numbers or approximate.
Practice 2
Ex 3-Solve Using Different Methods
• Solve by any method:
• Choose the best method
based on the given
equation.
1) Graphing
2) Factoring
3) Square Roots
4) Complete the Square
5) Quadratic Formula
Practice 3
METHODS TO SOLVE
Graph
Factor
Square Roots
Complete Square
Quadratic Formula
Solving Quadratics
Review
• What is the quadratic formula?
• What other method of solving quadratics is
used to derive the quadratic formula?
• What are the methods we can use to solve a
quadratic equation?