Lesson 13-6 Pages 692-696

Graphing Quadratic and

Cubic Functions

What you will learn!1. How to graph quadratic functions.

2. How to graph cubic functions.

What you really need to know!

To graph a quadratic or cubic function, make a table of values and plot the points.

Example 1:

Graph the function:

y = -2x2

y = -2x2

xx yy

-2-2 -8-8

-1-1 -2-2

00 00

11 -2-2

22 -8-8

Example 1b:

Graph the function:

12

2

x

y

xx yy

-2-2 33

-1-1 1.51.5

00 11

11 1.51.5

22 33

12

2

x

y

Example 1c:

Graph the function:

y = -x2 – 3

y = -x2 – 3

xx yy

-2-2 -7-7

-1-1 -4-4

00 -3-3

11 -4-4

22 -7-7

Example 2:

The height of a triangle is 4 times its base. Write a formula for the area and graph it. Find the area of the triangle whose base is 3 units.

Example 2:

The area of a triangle is found by using ½bh. If h is 4b then;

½bh = ½b(4b) = 2b2

Example 2:

½bh = ½b(4b) = 2b2

If the base is 3, then:

2(3)2 = 18 units2.

a = 2b2

bb aa

00 00

11 22

22 88

Example 3:

Graph the function:

2

3xy

xx yy

-2-2 44

-1-1 1.51.5

00 00

11 -1.5-1.5

22 -4-4

2

3xy

Example 3b:

Graph the function:

y = 2x3 + 2

y = 2x3 + 2

xx yy-2-2 -14-14-1-1 0000 2211 4422 1818

Page 694

Guided Practice

#’s 4-10

Pages 692-694 with someone at home and

study examples!

Read:

Homework: Pages 694-696

#’s 12-30 even

#’s 38-48 all

Study Guide and Review

Pages

698-700

#’s 1-30(Odd answers in back of book)

Prepare for Test!

Page

701

#’s 1-25

Prepare for Test!

Pages

702-703

#’s 1-8

Page

757

Lesson 13-6