Casio fx 991ms

SOURCE: 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

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...

SOURCE: how to calculate inverse of a 3x3 matrix in casio

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

SOURCE: Hi, I have a Casio calculator fx-991MS giving me wrong answers!

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.

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SOURCE: can you please help me

This will show you how to do statistics (calculate average, standard deviation, regressions etc.) as to the mode and median refer to the definitions.

TO COMPUTE STANDARD DEVIATION AND 2-VAR STATISTICS.

I assume you know the theory. I will show you the key strokes

For 1-Var statistics
Press [MODE][3:STAT] [1:1-VAR]. You are ready to enter values in the X column.
Enter a number and press [=]. Cursor jumps to second number to enter.
Keep entering numbers and pressing [=] till all numbers are in. Press the [=] key after the last one.
Press [AC] key to clear the screen.
Press [SHIFT] [STAT] (above digit 1.) then [5:Var]. Screen displays the statistical variables 1:n ;2: x bar; 3: x sigma n; 4:x sigma n-1.
Press the number corresponding to the statistical value you want, ex 1:n . The variable appears on screen. Press [=] and it will be displayed.
To display another variable press [SHIFT][STAT][5:Var][ 1,2, 3, or 4] .

To access the sum of squares sigma x^2 and the sum of data sigma x press[SHIFT][STAT][4:SUM] then [1: for sigma x^2] or [2: for sigma x]. Press [SHIFT][STAT][6:MinMax] to access minX and maxX.

For 2-var statistics
To perform 2 variable statistics you press [MODE][3:STAT] and any of the other regression options (except 1:1-Var). A two column template opens where you enter the X and Y values. When finished entering data, press [SHIFT][STAT][5:Var]. to access the different statistics. As I assumed above, you should be able to recognize what each variable means.