How do I solve a matrix? I have the manual but do not understand it

The FX-991ES offers simple matrix operations like basic arithmetic, plus the slightly more complex operations determinant and inversion. Furthermore, it is limited to matrices with a maximum size of three rows and three columns.

The rank of a matrix is defined as the number of linearly independent row or column vectors. You can perform a simple partial test for square matrices by calculating the determinant of the matrix:

1. Enter the matrix into matrix variable MatA.
2. Press [SHIFT] [4] [7] [SHIFT] [4] [3] [)] [=]

The display now should show det(MatA) and the determinant of the matrix in the result. If the determinant is not 0, the rank of the matrix equals the dimension of the matrix, otherwise the rank is less than the dimension.

Unfortunately, this is all support the calculator offers. For small matrices (i.e. 4x4 or smaller), you should familiarize yourself with the Gau? Elimination Method algorithm for solving linear equation systems. It is a two-step procedure where a matrix first is converted to its row echelon form, and second to row canonical form to solve the LES.
You need to follow the algorithm only through the first part, the number of non-zero rows after this step equals the rank of the matrix. With a little exercise you will be able to do it faster on paper than trying to do it with your calculator only.

For larger matrices I suggest to use a PC with more powerful math software (Maple, Mathematica, ...) or, if you know some basic computer programming, just write the necessary program yourself, which is also a very good exercise both in programming and understanding the algorithm.

What do you mean by "solve a matrix"? Find the inverse? Find the determinant? Find the solution to a system of linear equations? Within limits the fx-115ES can do any of these and more.

The procedures are described in the "Matrix Calculations" section of the manual. If you still have problems, please reply to this post specifying what you want to do.

Press MODE 6 to get into matrix mode. Note: do this only once. If you do it again, it will erase all your matrices. Pick the matrix, set its dimension, then the calculator will put up a screen allowing you to enter/edit the matrix elements. At any time you're in matrix mode, press SHIFT 4 to bring up the matrix menu.

All this is explained in the manual beginning on page E-57. If you've misplaced the manual, you can download a copy from
http://support.casio.com/manualfile.php?rgn=1&cid=004001004

Here check the manual:

http://support.casio.com/manualfile.php?rgn=5&cid=004001004

Here is copy of the answer I posted to a question on how to use Matrices. Read it carefully. It helped a few people, and there is no reason why it should not help you too. If after a bona fide effort to understand it you still have a problem, post a comment here. What I am saying, is do not just shoot the answer, try it first.

First you must set Matrix calculation
[MODE][6:Matrix].

1. Then By entering one of the numbers [1:MatA] or [2:MatB] or [3:MatC] you get to choose the dimensions of the matrix (mxn)
2. Once finished entering the matrix you clear the screen.
   

The operations on a single matrix are available by pressing[Shift][Matrix]. They are

• [1:Dim] to change the dimension of a matrix (in fact redefining the matrix)
• [2:Data] enter values in a matrix
• [3:MatA] access Matrix A
• [4:Matb] access Matrix B
• [5:MatC] access matrix C
• [6:MatAns] access the Answer Matrix (the last matrix calculated)
• [7:det] Calculate the determinant of a matrix already defined
• [8:Trn] The transpose of a matrix already defined
  

Operations involving 2 matrices

1. To add matrices: MatA+MatB
2. To subtract: MatA-Matb
3. To multiply: MatAxMatB
4. To raise a matrix to a power 2 [x2], cube [x3]
5. To obtain inverse of MatA already defined MatA[x-1] where [x-1] is the x to the power -1 key

Dimensions of matrices involved in operations must match (see you textbook for the rules). Read the appendix to your user manual, there are several examples.

Here is copy of the answer I posted to a question on how to use Matrices. Read it carefully. It helped a few people, and there is no reason why it should not help you too. If after a bona fide effort to understand it you still have a problem, post a comment here. What I am saying, is do not just shoot the answer, try it first.

First you must set Matrix calculation
[MODE][6:Matrix].

1. Then By entering one of the numbers [1:MatA] or [2:Matb] or [3:MatC] you get to choose the dimensions of the matrix (mxn)
2. Once finished entering the matrix you clear the screen.
   

The operations on a single matrix are available by pressing[Shift][Matrix]. They are

• [1:Dim] to change the dimension of a matrix (in fact redefining the matrix)
• [2:Data] enter values in a matrix
• [3:MatA] access Matrix A
• [4:Matb] access Matrix B
• [5:MatC] access matrix C
• [6:MatAns] access the Answer Matrix (the last matrix calculated)
• [7:det] Calculate the determinant of a matrix already defined
• [8:Trn] The transpose of a matrix already defined
  

Operations involving 2 matrices

1. To add matrices: MatA+MatB
2. To subtract: MatA-Matb
3. To multiply: MatAxMatB
4. To raise a matrix to a power 2 [x2], cube [x3]
5. To obtain inverse of MatA already defined MatA[x-1] where [x-1] is the x to the power -1 key
   

Dimensions of matrices involved in operations must match (see you textbook for the rules). Read the appendix to your user manual, there are several examples.
Hope helps

Hi,
I do not have the calculator, so I checked the whole manual. There is no reference to matrices. So you cannot use use this calculator to solve matrix problems.

Sorry.
That should not prevent you from rating the solution.

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

According to the manual for the Casio FX115ES, the largest matrix it solves is a 3x3.

If I understand your problem correctly it sounds as though when you watch your TV through the tuner you get nothing (no sound or picture) but when you watch it through the Aux inputs (with DVD or VCR) everything is fine. If that is the problem you either have a bad tuner or a bad matrix IC. I've seen both problems in this model and the cost to fix either is about the same. If you know TV safety and can solder unplug unit, remove the back, remove the main circuit board, remove the tuner from the board. This web address http://www.moteva.com/shop/customer/home.php?cat=267 has an original tuner for $18.00 US plus shipping. Install the new tuner and give it a try. If all went well this should solve your problem. If not you will probably need a service manual to locate the matrix IC. http://www.servicemanul.net for $16.00 US as a download. Locate the matrix IC. It should be on a vertical board on the left side. You should be able to get it at this website http://www.tritronicsinc.com This should resolve all your problems. If you can't solder or do not understand electronics you should have a repair tech fix it. Cost should not exceed $100 to $150 US. A free solution would be to hook up a VCR to the Aux input and use the tuner on the VCR and forget about trying to get channels through the TV tuner. It's your choice. Good luck and remember safety.