2-7 The Quadratic Formula and Completing the Square The Quadratic Formula
You probably know the quadratic formula already. Here I am going to show you the derivation of the quadratic formula. Why here? It comes from completing the square. So now that you know completing the square you can understand where the quadratic formula comes from. You don’t need to repeat it; I just want you to follow this process.
The Discriminant The quantity is called the descriminant. Understanding the value of simply the descriminant allows you to evaluate the answer you will get. 2 real roots But what about the graph? 1 rational root But what about the graph? 2 imaginary roots But what about the graph?
Example We are going to graph then QF so that you can see what the QF actually lets you find. • Graph then solve • Graph then solve 3. Solve