Question about Texas Instruments TI-89 Calculator

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Doesnt solve integrates and derivatives

Whenever i try to solve an integrate or a derivative a message appears that says "non-algebraic variable in expression" i do exactly what the guidebook says...i even did the examples it had in it but that message appears in that situation too... what should i do???

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If you are using X as your variable try this. Hit the F4 key, press 4 and type X. This will delete the variable x from memory and you should be good to go.

Posted on Oct 04, 2007


Try clearing the memory of all the variables..that might solve the problem mohit

Posted on Oct 01, 2007


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1 Answer

Error: Non-algebraic variable in expression

Non-algebraic variable in expression: error 790
If a is the name of a PIC, GDB, MAC, FIG, etc., a+1 is invalid. Use a different variable name in the expression or delete the variable.

Apr 22, 2015 | Texas Instruments TI-89 Graphing Calc...

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How would i solve for an expression and be able to leave it in terms of the variable, like (2a-1)(8a-5) and get the answer with the variable in it

This calculator cannot manipulate algebraic expressions. You can enter an expression and generate a table of values. You can enter an equation in one unknown and solve it. But you cannot do algebra.
You would need a calculator that has a Computer Algebra System (Algebra FX 2.0, or ClassPad 300/330). Sorry.

May 10, 2012 | Casio FX-115ES Scientific Calculator

1 Answer

Error:non-algebraic variable in expression

Non-algebraic variable in expression error may occur if a is the name of a PIC, GDB, MAC, FIG, etc., a+1 is invalid. Use a different variable name in the expression or delete the variable

Mar 21, 2012 | Texas Instruments TI-89 Calculator

1 Answer

How can i solve integrals with ALGEBRA FX 2.0 PLUS

The syntax for the evaluation of definite integrals (integrals with boundary limits) is as shown on the screen capture below.

$ (function , variable , lower bound, upper bound)
By default the name of the dummy variable is x. If you use another name, the variable must appear as an argument of the function, and as variable.


Mar 13, 2012 | Casio Algebra FX 2.0 Calculator

1 Answer

I reset the settings in my ti-89 titanium calculator and now when I use an e in a derivative the calc says: Error: non-algabraic variable in expression. How do I restore settings to allow for solving...

If e is in the name of a PIC, GDB, MAC, FIG, etc, then e+1 is invalid. And you will get a error 790, Non-algebraic variable in expression. Use a different variable name in the expression or, go to the VAR-LINK screen and, find e. It is probably in a folder that you have been working in. Once your in VAR-LINK go down to the folder your working in and, open it up. Go down to e and see what else got called e. Highlight e and, if there is no symbol to the left of it, you can delete it. Press [F1] [1] [ENTER]. If it does have a symbol like a lock or, an asterisk then you have to unlock or unarchive it first before you can delete it. You can find those commands by pressing [F1] then press [7] or [9], respectively. Once it is unarchive or unlocked you can highlight it and, delete it with [F1] [1] [ENTER].

Dec 12, 2010 | Texas Instruments TI-89 Calculator

1 Answer

Derivative feature does not work

The newer version of the OS is quite different from the initial version. It would be a good idea to upgrade the OS.
Back to your question. Since I upgraded my calculator, I am unable to illustrate the calculations with screen captures that are meaningful to you. If you do not mind I will show you how to calculate derivatives and integrals using OS Version

In Calculator Mode
  1. Press the Menu button.
  2. Use down arrow to highlight 4:Calculus or just press 4
  3. Select 1:Numerical derivative at a point and press ENTER
  4. An entry screen opens where you can select the name of the independent variable (default is x, not X), the point where you want the derivative and whether you calculate the first or the second derivative.
  5. After you make your choices, you press ENTER and a template is displayed in calculator screen.
  6. All you have to do then is to specify the function you are differentiating.
Here are a few screen captures to illustrate the process.




For the numerical integration
Select Calculus (see above)>Numerical Integration>ENTER.
Type in your integral using the template. Here is the procedure illustrated.



May 28, 2010 | Texas Instruments TI-Nspire Graphic...

1 Answer

TI 89 when solving equations or integrating a message appears:

With the ALPHA keyboard, Type in the NewProb command and press ]ENTER] It resets the one-letter variables to their default status.
Alternatively, you can use the CATALOG of commands to launch the NewProb command.
Another way is
In HOME directory, press the [2nd][F1] to activate the F6 key. In the menu list, press 1:Clear a-z and ]ENTER].
If you have to use the variable x multiplied by a function (sin, cos, tan, log, etc) do not used implied multiplication: enter the [*] explicitly.

Apr 14, 2010 | Texas Instruments TI-89 Calculator

1 Answer

Differentiating and Integrating Problems

This means that you are using a non-algebraic variable in an expression. I know, I am not even paraphrasing. Exemple: if you write 2 + johnQ, where johnQ is a table of data, a picture or a GDB, graphical data base object.

8d787a6.jpg Here is an exemple where mat is a 2X2 matrix and mot is a table.
Hope it helps.

Sep 14, 2009 | Texas Instruments TI-89 Calculator

1 Answer


for expand, you don't need to put ",x" at the end.

just do: expand( (x-5)^3 )
and you should get: x^3-15x^2+75x-125

May 09, 2008 | Texas Instruments TI-89 Calculator

4 Answers


On the home screen, go to F6 ([2nd] [F1]) and then press [2] (NewProb). It should fix the problem.

Feb 15, 2007 | Texas Instruments TI-89 Calculator

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