The Virtues/Importance of Graphing/Guessing

Introduction

Graphing calculators are incredibly useful tools. I will be providing a quick overview here using the TI-89 standard calculator, which is a classic calculator. All graphing calculators will generally be able to perform the same basic functions, but the keystrokes will probably be different.

Getting started

Ignoring the small print above the keys for a moment, let's look at the basic things you can do with the TI-89. There is a number pad, with the basic operands just to the right, as well as the "enter" button for you to input your questions. To the left is the on button, the equals sign, and some other specialized keys. Above are the parentheses, commas (important especially when running functions in the menus), variables, backspace button (looks like <-), exponent button (looks like ^), and buttons to access other menus, or move between calculations (the arrow buttons). An important thing to note is whenever you are in a menu or secondary screen, you can press ESC or HOME to get back to the main screen.

Also important to note are the keys for accessing secondary functions. On the TI-89 there are three keys with the purpose of accessing secondary functions (written in colored print above the normal keys; the color corresponds to the color of the special keys) - the "2nd" button (orange-colored), the "alpha" button (purple-colored), and the green button with a diamond on it. These, plus the up arrow (which allows you to make letters uppercase) and all of the menus will allow you to access everything on the graphing calculator.

We'll look at the menus later, but first I'd like to point out the highlights of the secondary keys. The alpha secondary key allows you to access letters; A is located at the equals sign and W at the decimal point. X, Y, and Z are already included as standard variables. If you are typing documents or coding in programs, I'd recommend pressing the 2nd button and then the alpha button, locking in the alpha so you can press the letter keys without having to continually press the alpha key. The second key allows access to important menus, as well as less than/greater than, square roots, brackets (curly and square), sin, cos, and tan, $\pi$ , $i$ , the degree symbol, $\int$ , $d$ (located right next to each other on 7 and 8), and others.

Menus

working on it

Special and Noteworthy Functions

Let's look at the function a graphing calculator is named for: graphing. First, press the diamond button