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

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.

Quote:

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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.

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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.