# ti 89 titanium calculus malfunction

• Apr 15th 2009, 05:26 PM
hrrensch
ti 89 titanium calculus malfunction
I've got a ti 89 titanium and one of its many valuable qualities is its ability to integrate and differentiate.

However, just recently, it have not been functioning correctly. When I try to calculate indefinite integrals or derivatives, my calculator returns a number instead of an expression.

Ex:
entered ∫xdx
keystrokes:[2nd] [∫] [X] [,] [X] [)]
returns: 25/2

entered d/dx(x^2)
keystrokes:[2nd] [d] [X] [^] [2] [,] [X] [)]
returns: 10

The calculator should be returning expressions involving the variable in question. I have no equations in the y editor, no programs that I have created or are aware of that might cause this and I have tried removing all the batteries with the idea in mind that it might reset the defaults. No luck.

Any suggestions?
Thanks
• Apr 15th 2009, 05:30 PM
Jameson
Going by your two examples the calculator is using x=5. You might have just saved this value. I forgot how exactly but there is a way to clear all stored data of this sort. Look around in the memory or maybe someone else can tell you explicitly. Luckily it's calculating the problems correctly for x=5.
• Apr 15th 2009, 06:16 PM
Reckoner
Quote:

Originally Posted by Jameson
Going by your two examples the calculator is using x=5. You might have just saved this value. I forgot how exactly but there is a way to clear all stored data of this sort. Look around in the memory or maybe someone else can tell you explicitly. Luckily it's calculating the problems correctly for x=5.

I agree. This is not a malfunction.

Press F4 to open the "Other" menu, and select "4:DelVar". Delete x with "DelVar x" and you should be okay. You can also press [2ND] [VAR-LINK], scroll down to x, press F1, and choose Delete.