Homework 2: Simple programming of the TI-83

Exercise 2

Simple Programming of the TI-83

Work through this short exercise to create a simple program!

Assume you want to be able to quickly calculate the percent difference between two experimental values. Percent difference is typically found via the following calculation:

percent difference = | first value - second value | x 100

0.5 (first value + second value)

Because you will be doing such a calculation many times during the school year, you decide to create a calculator program to carry out this tedious task.......

Press [PRGM] on the calculator.
Select (NEW ) in program menu bar and notice that the only option is Create New. Press [ENTER] to execute the Create New option. This initiates the programming mode.
Type in the name PCNTDIFF letter by letter. Press [ENTER]. You should see PROGRAM:PCNTDIFF at the top of the screen. Your cursor should be just to the right of the first :.
You are now ready to type in the commands of the program line by line. A : denotes the beginning of each command line in the program. Below are some guidelines for entry of this program:

Quote symbols and the characters within them must be typed letter by letter, including the spaces.
Commas and parentheses must be typed in.
The symbols for the variables (in this case letters A and B) must be typed in wherever they appear.
The operators +, -, and / must be typed in.
Numbers must be typed in.
There are special built-in commands in the calculator and you cannot simply type them in letter by letter. The commands ClrHome, Disp, Input, abs, and Stop are a few of these special commands and must be entered from the list found in the TI-83 "catalog".

For example, the first line of the PCNTDIFF program is entered by first following steps 1-3 above so that your cursor is at the first : in the program’s screen. Then you access the catalog by pressing [2nd] [CATALOG]. You can hit the first letter of the command name (in this example, the letter C) to reduce the amount of scrolling you will have to do to select the command you want. Use the arrow keys to scroll to the ClrHome command. Hit [ENTER] and notice that the ClrHome command now appears in the first line of the PCNTDIFF program. To signify that you have completed the first line of the and wish to progress to entry of the second line of the program, hit [ENTER]. Your cursor should move to the next : .

The program lines should look as follows when you are done.....

:ClrHome

:Disp "FIRST VALUE"

:Input A

:Disp "SECOND VALUE"

:Input B

:Disp "PERCENT DIFF= ",abs(A-B)/((A+B)/200)

:Stop

Note: If you accidentally get knocked out of programming mode, there is a way to get back into the PCNTDIFF program. Press [Prgm] and select [Edit] from the menu bar. Then choose the PCNTDIFF program and resume your editting.

When you have entered the last line of the PCNTDIFF program, press [2nd] [QUIT] to leave the programming mode.

Access and run your PCNTDIFF program to make sure it works!

***** Challenge1! Write your own program to calculate the percent error between an experimental value and a "known" or theoretical value. Give your program a meaningful name up to eight characters long.

***** Challenge 2! Write your own program to solve quadratic equations. This is just a bit more complicated than the percent difference program. Give your program a meaningful name up to eight characters long. Neat!