These are questions that students in classes that
use the TI-89 often ask. If you are having a particular difficulty, it is
likely the answer to your question is in the list below. Links to particular
sections are included to help you find the answer you need.

### 1. My graph doesn't look right.
Why not?

When a graph doesn't "look right"
it is most likely because you have either entered
the function incorrectly or you have not set
the window properly.

### 2. The graph is not showing on
the screen. What's wrong?

There are two main reasons that a graph may
not show up.

a) The function may be turned off. From the
Y=Editor window turn functions off by pressing F5 and make a selection.
You can also press F4 to select a single function to be turned on.

b) Your window
may not be set correctly.

### 3. The graph has no axes. How
do I turn them on?

The axes can be turned on and off with the
FORMAT menu.

### 4. Why am I getting the message
ERR0R 12: DIM MISMATCH?

This message is shown when you have a statistical
plot turned on and there are no values in lists
to graph or they are not evenly matched. You need to turn the plot off.

### 5. Why does my trace have different
coordinates?

The FORMAT
setting will determine whether rectangular or polar coordinates are shown.

### 6. When I try to graph a function
the screen has r1 or x1t and y1t on it instead of y1. How do I get a y1?

The MODE
setting will determine the type of graph that can be drawn.

### 7. Why can't I enter the values
I want to in the TABLE?

The TABLE
must be set to ASK before you can enter the values you want.

### 8. Can I solve an equation or
check an equation using a graph?

You can solve an equation if you can enter both
sides of the equation into the graph editor and use intersect
to find the solution.

### 9. How can I check an answer
to an equation on the Home Screen?

You can store
the answer in the variable X and then enter the expression to check your
answer.

### 10. How can I edit a line without
having to retype the entire expression?

You can use the storage
area ENTRY to recall several recent entries.

### 11. I'm entering an expression
in the home screen but the answer is wrong. How can I correct this entry?

There is a good chance that your expression
has not been entered with the proper placement of parentheses. You must
enter parentheses to maintain the proper order of operations.

### 12. How can I make the screen
darker or lighter?

Press
to lighten the screen, and
to darken the screen.

### 13. I can't remember where a
function is. What do I do?

The CATALOG
menu has every function, variable, list, etc. in the catalog. You may want
to create a CUSTOM
menu.