Six Tips for Using a Graphing Calculator

Here are a few tips to keep in mind when using a graphing calculator.

Using a Graphing Calculator Tip #1- Multiple Graphs

Multiple graphs can be displayed at the same time for easy comparison. To keep it clear which graph is which, the style of each graph can be changed. To change the style for a graph, hit the “Y=” key and then use the left arrow until the blinking cursor is on the “\”. By hitting enter, different styles can be chosen. Different styles include boldfaced, normal and layered.


Using a Graphing Calculator Tip #2- Changing the Table Values

By default, the initial value for X is 0 and X is incremented by 1. To change these values, the TBLSET option should be used. For example, if it is desired to see a .25 change between values, then the delta (triangle shaped symbol) Tbl value should be changed to .25. Similarly if it is needed to see values starting at 100, the TblStart value should be changed to 100.


Using a Graphing Calculator Tip #3- Order of Operations

To be sure the calculator is doing what is expected, it is critical that parenthesis are used when needed. This is especially true when dividing polynomials or just simply having multiple terms in the numerator and denominator. To ensure the correct solution, surround the numerator with parenthesis and do the same for the denominator. Similarly when multiple terms are in an exponent, parentheses are necessary. For example, if X <> 1 or 0, 5^2X is different from 5^ (2X).


Using a Graphing Calculator Tip #4- What is Wrong with my Calculator?

There are various occasions when what is displayed doesn’t look correct, but it is not clear what was done wrong. One time this can happen is when you are just starting out with Trig. One of the first things you learn is that the sin of 30 degrees is .5; however, the calculator is showing-.9880316241. The problem is that the calculator is in radian mode. This can be resolved by pressing the MODE key, then moving the cursor to the Degree option, pressing ENTER and then QUIT. Trying sin (30) will now give the “correct” value, in degrees this time.


Using a Graphing Calculator Tip #5- What is Wrong with my Calculator Again?

Another time when it might not be clear what happened to your calculator is when you are trying to view the table values and values are missing. This can easily be resolved by pressing the TBLSET key and making sure the independent and dependent options are both set to “Auto” and not “Ask”. By moving the cursor to the “Auto” selection and pressing the enter key, all will be right with the world. After making this change, try viewing the table values again.


Using a Graphing Calculator Tip #6- What is Wrong with my Calculator (the last time)?

The negative sign “(-)” and the subtraction sign “-“ if mixed up will give a syntax error. For example 6(-) 6 is a problem. Simply retrying using 6-6 will fix the problem. Aside from these aforementioned issues, the easiest thing to do when your calculator is “broken” is to reset it. By hitting the MEM key and then choosing the “ALL RAM” option, everything should be OK. If that doesn’t work, remove the batteries for a few minutes and then put them back.

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