4.4 Notes: Solve Quadratics by Graphing and Factoring

4.4 Notes: Solve Quadratics by Graphing and Factoring

Objective

To solve quadratic equations by factoring.

Recall

Zeros of a Function

The zero of a function is the value of the input x that makes the output f(x) equal 0.

What are the zeros of the function that is pictured here?

It's not always convenient to graph a quadratic and try to find its zeros from a graph, although technology makes that job easier:

The Zero Product Property

Open Ended

Factor

$$x^2-10x+21$$  

So let's take it a step further.

Super-Important Information

The equation must be solved for 0

before you can use the Zero Product Property. If you have something other than 0 on one side of the equal sign, you must solve for 0 first before factoring.

Open Ended

Solve

$$x^2-10x+21=0$$  

Poll

Select the image that most closely you feel about being able to solve quadratic equations by factoring;

• Seriously Mr. Dull? That's the worst joke I've ever heard.

Guided Practice

Complete the remainder of problems #1 - 8 on your 4.4 Notes handout.