Question about Casio FX991MS Scientific Calculator

# How to multiply the matrices using fx-991ms calculator

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The following was written for the Casio FX-991 ES. If matrix calculations are available on your calculator you will perform them as described below. ( I have no time to verify that the FX-991ms can perform matrix calculations).

Let me explain how to create matrices. (If you know how to do it, skip to the operations on matricies, at the end.)

First you must set Matrix calculation
[MODE][6:Matrix]. 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]. Once finished entering the matrix you clear the screen.
The operations on matrices are available by pressing [Shift][Matrix]
[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

To subtract MatA-MatB
To multiply MatAxMatB
To raise a matrixe to a power 2 [x2], cube [x3]
To obtain inverse of MatA already defined MatA[x-1] [x-1] is the x to the power -1 key
Dimensions of matrices involved in operations must match.
Here is a short summary

The multiplication of structured mathematical entities (vectors, complex numbers, matrices, etc.) is different from the multiplication of unstructured (scalar) mathematical entities (regular umbers). As you well know matrix multiplication is not commutative> This has to do with the dimensions.

An mXn matrix has m rows and n columns. To perform multiplication of an kXl matrice by an mXn matrix you multiply each element in one row of the first matrix by a specific element in a column of the second matrix. This imposes a condition, namely that the number of columns of the first matrix be equal to the number of rows of the second.
Thus, to be able to multiply a kXl matrix by am mXn matrix, the number of columns of the first (l) must be equal to the number of rows of the second (m).

So MatA(kXl) * MatB(mXn) is possible only if l=m
MatA(kX3) * Mat(3Xn) is possible and meaningful, but
Mat(kX3) * Mat(nX3) may not be possible.

To get back to your calculation, make sure that the number of columns of the first matrix is equal to the number of rows of the second. If this condition is not satisfied, the calculator returns a dimension error. The order of the matrices in the multiplication is, shall we say, vital.

Posted on Nov 07, 2012

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Posted on Jan 02, 2017

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

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

Hope it helps

Posted on Sep 07, 2009

SOURCE: m mod n in Casio fx991MS

there is one button ab/c beneath CALC... if u want to calculate 7 mod 4 then... u should press 7 then ab/c 4 and equal to
1, 3 ,4 which is 4*1=4 and 7-4=3 remainder...

Posted on Jun 29, 2009

Hello,
I am only looking for a plausible cause of the error, because I do not believe your calculator can make such a mistake. I think you accidentally activated the Exponential display format and did not pay attention to the small, raised -03 that came at the end of the number displayed. It is a common mistake for those not very familiar with Scientific or exponential notation.

Let us try to reset your calculator to the normal (floating point) format.
Press the [MODE] key a number of times until you reach a screen that has FIX, SCI, NORM and under each one a number (FIX 1, SCI 2), Norm 3). To have the number of decimal place you gave in your result (4 decimal digits), you press 1 to select Fix then 4.

Be aware that scientific calculators usually stop displaying results in floating point format ( 0.0000045 ) if the number is smaller then 0.001. So basically, 0.00099 will be displayed as 9.90-04, -04 being raised above the level, and in smaller size.

Hope it helps.

Posted on Oct 02, 2009

Testimonial: "Thanks so much, its working now:) I thought I was going to have to buy a new calculator!"

press shift then log then insret the no you want to find antilog and press equals( =)

Posted on Mar 14, 2010

If you want to get an answer like 1/2X for d/dx(X^2), you will have to purchase a CAS calculator like Casio's Algebra FX-2 or Classpad. TI series calculators also have CAS.
However, you can calculate the numerical values of derivatives and integrals only.
To calculate the value of a proper integral:

1. Press the 'ON' key;
2. Press the Integral key ;
3. Enter your expression (example X^2+X-3 etc);
4. Press the 'comma' key after your expression;
5. Input the first limit after comma, input comma again after first limit;
6. Close brackets;
7. Press the equals key, display may return after a while with the answer.
for eg to calculate xdx from 0 to 2, input as follows:

dx(X,0,2)

To calculate derivative at a point:

1. Press Shift and then the integration key.
3. Input comma;
4. input the point at which you want to evaluate the derivative;
5. Close bracket and press enter.
Example, to calculate d/dx X^2 at 3 input:

SHIFT+dx key X^2,3)

Display looks like this: d/dx(X^2,3).

Posted on Oct 23, 2009

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## Related Questions:

### Casio fx-991MS M+ button multiplies the answer then stores the value.

Whys use the M+ button? Every time you press it it adds the content of the display to the content of the running memory. Degree mode has on influence on the content of the memory.

Mar 11, 2015 | Casio Office Equipment & Supplies

### Shall we find rank of a matrix with casio fx-991ms???????????

This calculator can perform some operations on matrices with dimensions up to 3X3, but it cannot be used to find the rank of a matrix. Sorry.

Feb 25, 2014 | Casio FX991MS Scientific Calculator

### How to do matrix problems in fx991ms

The following was written for the Casio FX-991 ES. If matrix calculations are available on your calculator you will perform them as described below. ( I have no time to verify that the FX-991ms can perform matrix calculations).

Let me explain how to create matrices. (If you know how to do it, skip to the operations on matricies, at the end.)

First you must set Matrix calculation
[MODE][6:Matrix]. 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]. Once finished entering the matrix you clear the screen.
The operations on matrices are available by pressing [Shift][Matrix]
[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

To subtract MatA-MatB
To multiply MatAxMatB
To raise a matrixe to a power 2 [x2], cube [x3]
To obtain inverse of MatA already defined MatA[x-1] [x-1] is the x to the power -1 key
Dimensions of matrices involved in operations must match.
Here is a short summary

The multiplication of structured mathematical entities (vectors, complex numbers, matrices, etc.) is different from the multiplication of unstructured (scalar) mathematical entities (regular umbers). As you well know matrix multiplication is not commutative> This has to do with the dimensions.

An mXn matrix has m rows and n columns. To perform multiplication of an kXl matrice by an mXn matrix you multiply each element in one row of the first matrix by a specific element in a column of the second matrix. This imposes a condition, namely that the number of columns of the first matrix be equal to the number of rows of the second.
Thus, to be able to multiply a kXl matrix by am mXn matrix, the number of columns of the first (l) must be equal to the number of rows of the second (m).

So MatA(kXl) * MatB(mXn) is possible only if l=m
MatA(kX3) * Mat(3Xn) is possible and meaningful, but
Mat(kX3) * Mat(nX3) may not be possible.

To get back to your calculation, make sure that the number of columns of the first matrix is equal to the number of rows of the second. If this condition is not satisfied, the calculator returns a dimension error. The order of the matrices in the multiplication is, shall we say, vital.

Nov 07, 2012 | Casio FX991MS Scientific Calculator

### How to do matrix multiplication in scientifically calculator

Here is an account of what you can do with matrices on this scientific calculator. Certain precautions must be taken as concerns the dimensions of the matrices. Refer to your text book on matrix algebra.
On this calculator the largest matrices you can define have dimensions 3X3.
1. First you must set Matrix calculation: Press [MODE][6:Matrix].
2. 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].
3. Once finished entering the matrix you clear the screen.
4. The operations on A SINGLE matrix are available by pressing [Shift][Matrix].
5. The choices 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

Once you have created a square matrix, for example matA.
You press
[Shift][Matrix] [7:det] [SHIFT][MATRIX][3:MatA], close the parenthesis and press [ENTER].

If you have defined two similar matrices (same number of row and same number of columns) you can ADD them or subtract them. The operation keys are Plus and Minus as for any number.
To multiply you use the multiplication sign. The matrices must be compatible (mxn) multiplied by (nxk).

Aug 10, 2011 | Casio FX-115ES Scientific Calculator

### Matrix calculations

First put the calculator into matrix mode. Do this by pressing [mode]
then [5] . Insert your matrices (you have 3 that can be saved in this calculator MatA, MatB, and MatC). Press the [ac] button, this will allow you to do calculations on the matrices. From here you use the calculation keys to do your calculations. There are many calculations that this calculator can do. A couple examples are: multiplying a matrix by a constant you would type in MatA x 4 = , or you could add two matrices of the same dimension by typing in MatA + MatB =, or you could find the determinant by typing in (det (MatA)) = .

Mar 17, 2011 | Casio FX-115ES Scientific Calculator

### How do i multiply to 4x4 matrices using fx-991 es ?

The enclosed screen capture shows all the possible dimensions for matrices on the Casio FX-991ES. As you can see the maximum dimension of any matrix is 3. You can only create matrices with dimensions less than or equal to 3.

Dec 01, 2010 | Casio FX-115ES Scientific Calculator

### How to calculate 0.3log(base 2)0.3 using fx-991ms calc

Your calculator knows only the decimal logarithms log or log_10 and the natural logarithms (ln or log in base e).
So you cannot compute directly the logarithms in any bases other than 10 and e.
A workaround consists in using the relation
log_b(a)= (log_10(a) ) / (log_10 (b))
or the relation
log_b(a)= ln(a)/ln(b)

Similarly
log_2(0.3)=ln(0.3)/ln(2)
As to the multiplicative factor you had at the beginning of your expression, just multiply the value obtained by one on the formulas above (both formulas will give the same result) by 0.3

Jul 18, 2010 | Casio FX-115ES Scientific Calculator

### I have a Casio fx-115ES; I have followed the manual for creating and multiplying matrices. The matrices have been simple, 2x2 for each, but it returns with "Dimension Error". Any suggestions? Thank you for...

Calculator should be in [MATRIX] MODE
Try the matrices 2X2 matrices matA [1,2,3,4] matB [5,6,7,8], Add them, subtract them, multiply them, take the square of each. If that works for these matrices, then it must be your data. Be careful with negative numbers. To enter those, you must use the change sign (-).

There is also the possibility that the instructions were misread.

Dec 14, 2009 | Casio FX-115ES Scientific Calculator

### How do i solve a matric problem with a TI- 83+

Hello,
You should try to use the correct heading.
Press [2nd][Matrix] right arrow to [EDIT][ENTER] to create the [A]
matrix. Exemple of a 3x3 Matrix [A].

Once the matrix [A] is created you press [2nd][MATRIX] -->[MATH]

You can add similar matrices, you can multiply matrices, subbtract them, raise a matrix to a power, extract the square root, etc...

Here are the other operations you can pefrorm on matrices. Sorry I cannot go into the detail of things;A minimun of theory is needed to be able to use the commands.

Oct 14, 2009 | Casio FX-115ES Scientific Calculator

### How to calculate log value in calculator with different base value

In any scientific calculator log2(n) can be  calculated with either ln or log function as follows

Log2(n)= ln(n) / ln(2)

Or
Log2(n)=log(n) / log(2)

both will give nearly the same answers

Dec 08, 2007 | Casio FX-300MS Calculator

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