Published on 09/05/2005

#### Activity Overview

Using the activity center and the Navigator software, the students will review ordered pairs, and the equations for horizontal, parallel, and perpendicular lines.

#### Before the Activity

If you are using the TI-Navigator System with the TI-73 you will need the attached .pdf file.

While in the Activity Center within the TI-Navigator Software
A) Under the pull-down menu "File"

B) Remove Background Image if there was one already loaded

C) Load Background Image by finding it on your hard drive - wherever you chose to download it.

Also use the pull-down menu "View" to
A) Use the default -10 to 10 screen/window

B) Select "Individualized student cursors"

To review the placement of ordered pair: Select "contribute points" and under "configure" allow them to submit one or two points, step size one, using "X" for the XList, "Y" for the YList, one at a time.

Students should be logged in and have them enter the activity center.

The directions are available in a Word file called "activity Information word File for Parallel horses.doc but this is not necessary for this activity.

You WILL need to download the Horses.jpg picture.

#### During the Activity

Instruct the student's to put a point on a horse's nose, and put a point at (-7,4) etc.

Each time stop activity, clear data (under the "Edit" pull-down menu), and begin again.

Discuss results with the names hidden.

Then change to "contribute equations" and "configure" letting every student submit one equation to be graphed.

Instruct the students' to submit equations for lines that go through BOTH horses noses. (example of easiest correct answer Y = -7) Allow for both horizontal and non-horizontal submissions and discuss the difference in the equations using the "equation" screen.

Ask students' to submit equations for lines that go through a certain part of the picture. Point at it with your cursor. For instance: Y = -5x - 22 goes through the left part of the halter on the left horse.

Under "equation-graph" type in the equation Y = -5x -22

Leave only this line on the picture.

Challenge them to get lines that go through the same part of the halter on the other horse, by making a horizontal translation.
(example: Y = -5x + 10)
This task can be repeated for many other parts of the similar matching horses.

Discuss. Then leave only Y = -5x -22 on the picture.

RESIZE the graph by going under the "view" pull-down menu and doing a "ZOOM Square." The line will no longer go through the halter at the same place but that's ok.

Ask them to draw lines (any lines) that are perpendicular to the line left on the screen. If you left Y= -5x - 22 the simplest line would be Y = (1/5) x. Discuss.

Now ask them to draw a perpendicular line that also goes through the very tip of any ear. An example would be
Y = .2x + 8.85

Increase difficulty: You can "mask teacher input" under the pull down menu "view."

#### After the Activity

To assess individual learning, turn on, and record who submitted correct and incorrect responses, use a "quick poll" to ask questions, or use the four question "learn check" document attached.