Using the TI-89

Home Screen This is where all “normal” calculator stuff is taken care of. The TI-89 does not have a squared key, instead all powers are entered using the carrot on right side under clear. Square root key is above the multiplication symbol, but all other roots must be entered as fractional exponents.

Examples 1) To get a decimal instead of a fraction or simplified expression you always use green diamond enter. Be careful, if you are just dividing and want a decimal, you may want to hit green diamond enter instead of enter then changing. Sometimes doing this makes it divide twice.

2) Now, what you really want to know 2) Now, what you really want to know! How to do calculus problems on the calculator. First let’s clear the home screen. F1 8

The calculus menu is F3. The only thing we have done so far is limits, so let’s see how this works. 3) 4) The one at the end shows a positive direction

Or if you want to do the same limit but from the left, you enter a negative number to show that. 5) Now, how about limits at infinity.

6) 7) 8)

How about graphing First, clear home screen. F1 8 Green diamond F1 takes you to y= You can graph anything from here. Let’s look at a few things: 9) Zoom (F2) #6 always first on normal functions

Check out the table. Green diamond F5 Check out the table. Green diamond F5. We can see where the asymptotes are by looking where y is undefined. You can change how far apart the numbers are on the table by going to table set Green diamond F4 and looking at delta x.

Graphing Trig Functions When graphing trig functions, we always want our calculators to be in radians. (Always radians for Calculus and degrees for Physics – so you must know how to switch back and forth as well as what mode you are in at anytime) Look at bottom of screen for either RadAuto or DegAuto. If not Rad -

Go to mode 4th item – highlight radians enter twice always to set Go to mode 4th item – highlight radians enter twice always to set. Once will not change it. Also, we need to zoom trig so that the x axis changes to intervals using pi. (F2#7) Let’s try a few graphs. 10)

It should look like:

How about secant or cosecant. You can’t use because these are inverses How about secant or cosecant? You can’t use because these are inverses. It is difficult to type in using sine and cosine so instead let’s use the catalog key. When you hit catalog it knows you will need a letter next so you do not use alpha, just the first letter of what you are looking for.

11) We start with y= then catalog then s (you will probably have to scroll some to get sec), then enter. Now type in above. Your graph should look something like:

That’s all for now, more later!