Casio fx-9750GII is giving the wrong answer, is it broken?

They're both giving you the same number.
1.953125E-03 means 1.953125 * 10^-3, which is 0.001953125 .

convert by pushing the a/b/c button

In the Run>Mat screen there is a tab at the bottom left of the screen. If you press F1 it opens the tab and shows you other tabs for the matrix functions.

For the reciprocal of a number, enter the number then press the key marked with an x^-1. You might have to use the SHIFT key first. For inverse of trigonometric functions use the SHIFT key followed by the function name. The inverse of LN is e^x. The inverse of log is 10^x. To calculate the inverse of a matrix, enter the name of the (already created) square matrix then press x^-1.

mode, matrix, 1 (MatA), setup your matrix, and press AC.Shift 4 (MATRIX), 3 (MatA), and then press x-1 (next to the log and arrow keys), and it should give you an answer.

The casio FX-570MS does not handle matrices. So you cannot create matrices, let alone invert them. Sorry.

The same way you would get the inverse of a number. Assuming you already have the matrix entered into memory, press SHIFT 4 to bring up the matrix menu, select the matrix whose inverse you want, then press the x^-1 key (just to the right and slightly below the big round cursor pad.

The log base 10 function has an inverse: It is the 10 ^x function. It shares the same physical key with the decimal log. Use [SHIFT][LOG].
The natural log (LN) has an inverse alos and that it the exponentila function e^x. It shares the same physical key with it.

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

Hello,
You cannot calculate the inverse of an arbitrary matrix. It must be a square matrix (nxn) with non zero determinant. Make sure dimensions m and n are equal. (2x2), (3x3)

To calculate its determinant [Shift][MATRIX] [7:det] [SHIFT][MATRIX][3:MatA] close the right parenthesis and [=].
If determinant is different from zero then you can calculate its inverse.
If matrix MatA has already been defined, you calculate its inverse as follows;
[SHIFT][MATRIX][3:MatA] [X^-1][=]. Use the X to -1 power , the one under [MODE].
For well-behaved matrices you calculate the inverse directly without worrying about the determinant.
Hope it helps.