Math Plane 

This tutorial will show how to input and graph a piecewise function. Also, using tables, editing graphs, adjusting windows, changing colors, and various features of the TI Nspire will be explored.

Project

Graph the following function:

Find f(9) and f(100) using tables

Step by Step Instructions and Illustrations

Turn on device

1: New Document

2: Add Graphs

Blank graph and Equation appear.

(If the equation didn't appear, try the "tab" button)

Enter the Piecewise Function

Press the "template" button (next to the "9")

Select the Piecewise function template.

Choose 3 function pieces ("OK")

Enter each equation and each corresponding domain.

x    ^   2   +   3

then, after the comma:   x    <    (-)     2

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***Note:  To get the inequalities menu,  "ctrl"   "="

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In the next line,

4

then, after the comma:   (-2)  <=   x  <   2

And, the third line,

(-)    2x     +    2

then, after the comma     x   "ctrl"  "="   and select >=   2

"Enter"

(A partial graph appears)

To Change Viewing Window

"Menu"

4: Window/Zoom

4:  Zoom-out

Enter

(Click enter to zoom out)

OR, to get a better view:

"Menu"

4: Window/Zoom

1: Window Settings

x min  -10

x max  10

y min  -20

y max  20

"OK"    "Enter"

(A better centered graph)

Tables and Values

To find f(9), open up the table.

"Menu"

7: Table

1: Split Screen Table

"Enter"

The table appears on the right.

Using the keypad, scroll down to 9.

The output is -16

To find f(100), change the table

"Menu"

2: Table

5: Edit Table Settings

Table Start: 100

"OK"   "Enter"

The output is -198

Then, to return to the graph,

"Menu"

2: Table

1: Remove Table

To Hide the Text

Place the cursor over the equations text

"Ctrl"  "Menu"

2: Hide

"Enter"

(the Text disappears)

To Change the Color

Place the cursor over a part of the graph

"Ctrl"   "Menu"

B: Color

1: Line Color

Select red (or another color)

"Enter"

To Change Line Thickness

Place cursor over function (over the lines)

"Ctrl"   "Menu"

3: Attributes

Select the line weight you'd like.

"Enter"

To Bring back the equation text

Place cursor over the graph lines

"Ctrl"  "Menu"

2: Label

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Webcomic #34 - "Math Nursery Rhymes" (5-27-12)

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Change -2x + 2  to  3x - 8. Then, find the minimum value.

"Menu"

3: Graph Edit/Entry

1: Function

(new blank function f(2) =   appears at the bottom)

***Press the up arrow on the keypad!

The piecewise function f(1) reappears.

Now, edit the equation..  (Use left arrow on keypad to move cursor to left... Then, use "del" key to delete)

"Enter"

The modified piecewise function appears.

To find the minimum value

"Menu"

6: Analyze graph

2: Minimum

Place the cursor on the left side.. Press the keypad

Move the cursor to the right side, shading over the minimum point....  Press the keypad again...

The minimum (2, -2) appears...

To Save your project

"Doc"

1: File

5: Save As

Enter the file name   (such as 'piecewise tutorial')

"Save"  "Enter"

You're Done!!

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Keys Used in this Project:

Piecewise Template:

Inequalities, functions, and domains:

Window/Zoom Menu:

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PRACTICE working with Piecewise Functions

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Table of Values:

Modifying the graph attributes Menus:

Piecewise Function Edit:

Analyze Graph Menu:

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Thanks for visiting. (Hope it helped!)

If you have questions, suggestions, or requests, let us know.

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