LESSON FIVE: Polynomial Function Graphs and Their Roots/x-intercepts
When a polynomial function is in factored form, we can easily determine its roots.
Ex. f x  2x  1x  3
The roots are whatever values for x that make each bracket equal to zero. Here the roots (or xintercepts are 1 and -3.
Ex. f  x   3 x  2  x  4
2
Here the roots are 2 and -4. Since the factor x  2 is squared, we call this a root of EVEN ORDER.
The root x  4 occurs an odd number of times (once), and we call this a root of ODD ORDER.
Note that you can find the degree of the function even though it is in factored form. Just count the
number of x’s you would get if you expanded. Using the last example….

2
You would have an x from the first bracket and an x from the second bracket. That is like
x  x  x or x 3 , so the degree is three.
Now complete the back of this handout using the graphing calculators.
After that, complete the homework below.
Hw. P. 91 #1iii, 2, 3