Im pressing the buttom that everyone is saying is the inverse key but it is saying error. i really need help with this.

To get the inverse trigonometric functions press the 2nd key then the trig function key. If you'll look at the key legends above the SIN, COS, and TAN keys you'll see the standard math notations for their inverse function.

The antilog ( Oh I hate this word) is the inverse function of the log. If you are talking about base 10 log (common logarithms) the antilog is the power of 10 function.( 10^x) If you are talking about the natural log (ln) the antilog is the exponential function e^x.
On most calculators, a mathematical function and its inverse share the same physical key. One function is marked on the key and the inverse on the faceplate. One is accessed directly by pressing the marked key, and its inverse is accessed by pressing 2ndF, 2nd of SHIFT followed by the key.
I hope it helps you find the appropriate key on your brand of calculator (whatever it might be.)

Not all matrices are invertible. The matrice must be square.The matrix must be non-singular: Its determinant must be different from 0. Your error comes probably from the key you used to calculate the inverse. Use the reciprocal key, the one marked with x^-1. If the marking is not ON the key, use the SHIFT button prior to pressing the relevant key.

Hi Robert9004x2,

If you want to examine the matrix you want to inverse and, the one that is given you trouble pressing [2nd] [MATRX]. Then stroll and, select the one you want to look at by pressing, [ENTER]. You'll have to press, [ENTER] again and, matrix should display at the Home screen. At the Home when you get to them your looking for the ones that are not square, like 2 by2 or 4 by 4 etc. You might need to re-edit this matrix so, that it is square.

Your trying to invert a matrix that isn't square you might be using using the proper key sequence to create a inverse matrix. Here what the correct inverse matrix look on the Ti 84 Plus Home screen.

And pictured below is a Matrix is being inverted by using the ^ and the -1 keys. Which to inverse a Matrix on the Ti 84 Plus you have to use the [x^-1] key.

This is not the proper way to inverse a Matrix on the Ti 84 Plus. The proper way to inverse of a matrix, the [x-1] key must be used, instead of pressing the sequence [^][-][1]. The [x-1] key is the official inverse key and is located right under the Math key. It is also the same key that you use to get to the matrix menus. The [^][-][1] sequence is only raising the matrix to the -1 power and, will cause an error too. If you need any more help, just post a comment and, I'll respond quickly.

your value is not within the domain of the function, that is why it's giving you that error message, try the value times -1, or -(your value)

Hello,
When you get the error press any key to suppress the error message. Put the calculator into PROGRAM mode and you will see the line where the error occurred.

Here is what the manual says for ERROR 4 (free translation)
The line number called is not used or does not exist (larger than 448); attempt to load a program line (instruction) where there is not enough space; line label inexistant.
My hunch is that you are attempting to divide by 0: The quantity of which you are taking the reciprocal (inverse function has another meaning) may have a 0 value.
Do not forget to check the input values.
Hope that will help you debug your program

Hello,
Here is the solution for th FX-991ES.
Hello,

The error may be due to the key you used to signifie inverse. It says in the manual that you should use the key x^-1 not the one used to input general powers.
Here is screen capture from the Appendix to the manual. The picture shows the sequence of keys to press to obtain the inverse of a 2x2 matrix. It is taken from page 41 of Appendix


The matrix used in the exemple is
a_11=2 a_12=1 a_21=1 a_22=2
Here is the link to download the manual and the appendix

http://support.casio.com/manualfile.php?rgn=1&cid=004001004
The link is for FX991ES. Look there foe you manual.

Hope it helps

Hello,
In parametric mode you are not drawing one function, but two functions X1(T) and Y1(T). If you use the DrawInv( command either on X1(T) or Y1(T) you get a syntax error.
However if you are drawing functions in Funct mode you can draw the inverse of the function that has been graphed.
Here is how you do it.

[2nd][Draw][8: DrawInv] [ENTER]
The command appears on the home screen, and you need to tell it the function it will act on. To do so press
[VARS] --> Y-Vars [1:Function]
and select the function you want, say Y1, if Y1 has already been defined.

DrawInv Y1 [ENTER]
Both Y1 and its inverse will be drawn.

Hope it helps.

Hello,

The error may be due to the key you used to signifie inverse. It says in the manual that you should use the key x^-1 not the one used to input general powers.
Here is screen capture from the Appendix to the manual. The picture shows the sequence of keys to press to obtain the inverse of a 2x2 matrix. It is taken from page 41 of Appendix


The matrix used in the exemple is
a_11=2 a_12=1 a_21=1 a_22=2
Here is the link to download the manual and the appendix

http://support.casio.com/manualfile.php?rgn=1&cid=004001004

Hope it helps

I had the same problem... all you have to do is reset the calculator:

Type:
2ndF
ALPHA
It'll give you a choice Mem (0) or Reset (1)... press 1
Then it'll say Reset? (0)... press 0

And your calculator should be as good as new!