Pre-Calculus Tutorial

Intro

Once students begin to take classes on pre-calculus or beyond, instructors begin requiring them to draw and solve for the graphs of an equation (or even multiple equations!) This task can be daunting, but a graphing calculator can save the day! These handy devices draw, trace, and even solve for aspects of a graph. In this tutorial, I will show you how to use almost any graphing calculator to form a graph of an equation or function.

Sample Problem

We are going to find the graph of the following equation using a graphing calculator:

x^5-4x

Solution

This is a very tricky graph to draw by hand so we are going to use our handy dandy graphing calculator. I am going to use a TI-89 Titanium, but most graphing calculators follow the same idea for entering and solving a graph. (If you need to acquire a graphing calculator, click

here

Now we have our calculator so let’s start! Click the ON button on the very bottom left of the TI-89. In order to create a graph we must first tell the calculator the equation we are using (that y=x^5-4x). To do this we need to use the Y Editor. Click the black “apps” button near the arrow keys on the TI-89 and then click “2” to access the Y Editor screen. Here you will see a screen with a list of y1=, y2=, y3=, y4=, and so on until around 30 or so. Each line is a space to write an equation for a graph. Therefore, we only need one for our single equation. Go to the line that says y1= using the arrow keys, click enter, and type in the equation x^5-4x. Click enter, then click the green diamond button and F3 to access the graph. Wait a few seconds for the graph to load, then voila! Behold your graph in all its glory! The graph will look like a sinusoidal wave. If you need more help, go to this