Working from the HOME screen:
on the TI-89 Titanium
 What's Available From the HOME Screen?
 From the HOME screen: Look at the top of the viewing window for the tabs indicated in this section.  As you begin, remember F1 - #8 to clear the HOME screen and F6 - Clean Up. F1 - Tools Clear HOME screen - F1 - #8 F2 - Algebra F3 - Calc F4 - Other F6 - Clean-UP TI-89 - right arrow or F6 from 2nd F1
 I can't get a decimal answer!!!
 AUTO, EXACT, APPROX Mode How can I get an approximate decimal answer? Auto mode (the default) will give exact answers (such as 1/3) instead of giving an approximate decimal answer.  If you want the approximate decimal at any time, press GREEN DIAMOND, ENTER. (You can see an approximation symbol  above the ENTER key.) In AUTO mode, the calculator will find an exact answers if it can.  If this is not possible, it will find a decimal approximation instead. In EXACT mode, the calculator will find exact answers if it can.  If this is not possible, it will give up. In APPROXIMATE mode, the calculator finds decimal approximations. Auto mode - using green diamond, ENTER to get the decimal value.

Computer Algebra System (Symbolic Manipulator):
Why this calculator is more powerful than the TI-84+ family.

 Expanding Expressions:    Press F2 and select #3 expand. Notice the “built-in” parentheses of this function.  Be sure to enter your expression with necessary parentheses.  Expand (x + 3)3 If you get ( x + 3)3 as an answer, you did not include the needed parentheses. Look out for parentheses! Factoring Polynomials: Press F2 and select #2 factor. Specify the variable as a parameter. Factor  x3 – 8 What about the complex factors of  x2 + 2x + 4 ? Press F2, arrow down to #A Complex, arrow to the right, choose cfactor. Solving Equations: Press F2 and select #1 solve. You must: specify the variable for which you are solving as a parameter. Solve for x: x2 + x – 6 = 0 If complex solutions are a possibility, press F2, arrow down to #A Complex, arrow to the right and choose csolve. The expand command will also do partial fraction decompositions. Notice how slight variations in syntax alter the results of the factor command. Finding Zeros (Roots) Press F2 and select #4 zeros. Specify the variable as a parameter. Notice the answer in set notation. Find the zeros of: x2 - 9 = 0 If complex zeros are a possibility, press F2, arrow down to #A Complex, arrow to the right and choose czeros.
Hints:

1.  Correcting an entry error:   If a formula is entered incorrectly, arrow
up onto the entry that needs correcting, press ENTER and fix the mistake.

2.  Answers are not what you expected:  Check to be sure you entered the
information correctly.  If yes, try running the Defaults and Clean Up.  This should clear
out any "strange" happenings in the calculator.

Defaults:  2nd Mem, F1, #1RAM, #2 DEFAULTS, ENTER

Clean Up:   F6 - Clean Up #1 Clear a-z

3.  Want to clean up the screen quickly for a new problem?

 Choose F6 #2 NewProb The NewProb is a utility that         1.    clears the HOME screen and history area. (F1 #8 also does this)         2.    deletes all single-letter variables. (F6 #1 also does this)         3.    unchecks (but doesn't erase) all the function definitions on the                Y= screen, so that they will not be graphed.  (from the Y= screen,                F5 #3 also does this)

4.  The calculator is hung up but good.

1.  Try pressing ON.
2.  If this does not help, remove one of the batteries.  Hold down (-) and  )  while you put the battery back in.
3.  Keep holding down these keys for 5 seconds longer.
4.  This will usually do the trick.