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A Basic Guide to the TI-85

Richard E. Little

University of Tennessee
Knoxville, Tennessee

This is a web version (1.0) of a guide that I originally wrote in the summer of 1994, based on class handouts that I gave during the previous academic year. It was modified in the summer of 1995 and now is in it's final written form. For more info, see the introduction. If you have any comments you can e-mail me at rlittle@math.utk.edu.

All material here is © 1996 Richard E. Little. Feel free to print out a portion or all of this guide, just be sure to keep the copyright notice in place. If you are in the Knoxville area, you can get a hardcopy version of the original at Graphic Creations, located on the UTK campus at 1809 Lake Avenue (522-6221).

Detailed Table of Contents

Introduction

Conventions: How calculator keys and menu items are described; keys not mentioned

Part I: Basic Skills

1. Entering Expressions

Basic Math : using ; vs. ; handling SYNTAX ERROR.
Using Functions: order of entry; exercises showing the importance of parentheses.
Correcting Mistakes: using , , , and ; note and caution about .

2. Variables

Entering Names: using and ; exercise involving both.
Assigning Variables: using ; using variables in computations; practice exercise.
The Answer Variable: using ; note on when it is automatically inserted.

3. Functions

Accessing Functions: via menus, spelling out, and with ; exercise with .
Navigating Menus: using , , and .

4. Complex Numbers

Part II: Graphing

5. Background

Default windows and Range Settings: viewing window descriptions; how to alter the windows; explanation of [-10, -10, 1] by [-10, -10, 1].

6. Graphing Equations and Functions

Sample Equations and Functions: Examples to graph and what their default graphs look like.
Initial Setup: using .
Graphing : using , , and .
Saving Equations: clearing equations, including warning; deselecting with ; vs. .
Graphing the remaining equations and functions:(solving forbefore graphing), (actually graphing), and .

7. Incorrect Graphs

Sources of Error: human error; calculator error.
Incomplete Graph: example using odd root.
Too Much Graph: example using rational function.

8. Trace and Zoom

Algebraic Solution: Example to solve together with exact answer to check our calculator work against.
Graphing Two Equations Simultaneously: using ; entering two equations.
Finding the Coordinates of the Two Intersections: using , , , , and .
Finding the Third Solution: why solution must exist; using , changing xScl and yScl.