Elementary function arithmetic Puns

If you encounter any problems using these exercises, please write about it in the comments.

MultiplicationTableExercises

64 multiplication exercises from 2 * 2 to 9 * 9 presented in random order.

Link to use Multiplication Table Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/MultiplicationTableExercises.html

Link to use Multiplication Table Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/MTEforOldBrowsers.html

AdditionExercises

81 addition exercise from 1 + 1 to 9 + 9 presented in random order.

Link to use Addition Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/AdditionExercises.html

Link to use Addition Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/AEforOldBrowsers.html

SubtractionExercises

45 subtraction exercises from 1 - 1 to 9 - 9, without negative differences, presented in random order.

Link to use Subtraction Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/SubtractionExercises.html

Link to use Subtraction Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/SEforOldBrowsers.html

Versions for older browsers

Versions for older browsers are tested in Internet Explorer 8 and Android Browser of Android 2.3.3

How to use any Exercises offline

• Click Code => Download ZIP
• Extract MultiplicationTableExercises.html or any other .html file from downloaded zip archive
• Open MultiplicationTableExercises.html or any other .html file in your web browser
• Click START button to start exercises
• Click OK button to finish an exercise, or, while input field is selected, press Enter or Numpad Enter on keyboard (in versions for older browsers only clicking OK button may be working to finish an exercise)

Code on GitHub: [https://github.com/Telva

I'm making a game of connect in love2d(I don't know if I should post this to /r/love2d)

I'm trying to get a specific rectangle to rotate 90 degrees when you left click on it,

for this I make a function for distance to tell if the mouse pointer is close enough to a certain circle(switch1) when you click on it, and then call it in the love.update() function.

the relevant code:

function love.update(dt)
    local mousex = love.mouse.getX
    local mousey = love.mouse.getY
    local mouseToSwitch = distance(mousex, mousey, switch1x, switch1y)
    if mouseToSwitch < 50 and love.mouse.isDown(1) then
        rec1dir = rec1dir + 90
    end
end
function distance(x1, y1, x2, y2)
    return math.sqrt( (x2 - x1)^2 + (y2 - y1)^2 )
end

I run the game, and when I click anywhere inside the window I get this error:

Error

main.lua:52: attempt to perform arithmetic on local 'x1' (a function value)

Traceback

main.lua:52: in function 'distance'

main.lua:20: in function 'update'

[C]: in function 'xpcall'

**the line 52 mentioned in the error is line 10 in the code written above, and line 20 is line 4**

I've been doing some reading on the nuts and bolts of basic maths, following that Wikipedia rabbit hole essentially, and though I now feel more enlightened, I also have a lot more questions. My question for today is: exactly how are the elementary operations defined? I will take you through my thought process, which will reveal the precise nature of my confusion.

So, according to Uncle Wiki, an arithmetic operation like addition is a binary relation, meaning that it is a subset of (A×B)×C, where A×B is the domain of the operation and C is the codomain; in other words, it takes two elements and spits out a third. The elements of this subset are precisely those which satisfy the definition of the relation. With addition, {(2,4)} is related to {6}, but not {7}.

That's very easy to understand, at least intuitively. My stumbling block comes when I try to make this explicit, by which I mostly mean giving an expression in set-builder notation. All I can think of with that is something like {(a,b,c) ∈ ℕ×ℕ×ℕ | a+b = c}.

Do you see the problem? In defining addition this way, it was necessary for me to use another, unjustified definition of addition. It seems very circular. I would really like to know how addition (and the other operations) are defined from "first principles", if that makes any sense. I want to see it broken down into its most elementary parts and put back together. Can you help me with that?

Bonus question: the algebraic properties of an operation — commutativity, associativity, etc — are these conditions that we impose arbitrarily, or are they properties guaranteed by the definition of the operations themselves/axioms?

I am reading the source code of the NFLlib project. They use the shoup(x,y) function as if it is something well known here: https://github.com/quarkslab/NFLlib/blob/master/include/nfl/core.hpp#L596

But googling 'shoup', 'finite field', etc doesn't lead to its definition.

What might the shoup(x,y) function do?

I remember being expected to memorize multiplication tables in third grade. It occurs to me that it might have also been helpful to memorize addition and subtraction tables in a similar, rote kind of way. Is this something you remember being expected to do, or do most math practitioners just sort of develop a better intuition for fast addition and subtraction as they go?

For example, how would you solve 44^-1(mod667)? After calculating phi(667), you end up with 44^615(mod667), which would take ridiculously long to calculate without a calculator. And even then, most calculators cannot even go that high.

Hi. I am lost in this.
I have a table with a string column for mathematics functions:
TABLE A.RULE = ' 0.1 * (VAL1 * 0.9 + VAL2) '

I need create a query for convert two fields to one using the user predefined rule.

Example:
SELECT d.PK, d.VAL1, d.VAL2, f.RULE, dbo.fGetRuleValue(f.RULE, d.VAL1, d.VAL2) AS RULE_VALUE
FROM dbo.TB_DATA d,
dbo.TB_FIELD f
WHERE d.FK_FIELD = f.PK_FIELD;

I try with exec('SELECT @.r = ' + @.RULE) or sys.SP_ExecuteSQL('SELECT @.r = ' + @.RULE), but functions dont can call stored procedures and dynamic procedures.

My procedure dont going to make INSERTS, DELETES, UPDATES, ALTERS, DROPS or CREATES in the database...

I'm continuing to read through the text of Software Design for Flexibility, but I'm using Racket instead of Scheme.

I've encountered the part where they rebind arithmetic operators.

(define - #| new definition ... |#)

but before doing that they are able to store the original value of -

(define n:- #| somehow look original value of '- up in the 'system-global-environment |#)

However, Racket does not seem to have system-global-environment bound.

What would be the equivalent?

EDIT: I found make-base-namespace and namespace-variable-value which seem to do the trick.

I am using them like so:

(define (base-binding sym)
  (namespace-variable-value sym #t #f (make-base-namespace)))
(define n:- (base-binding '-))

A friend of mine proposed a question to me that necessitates that I know what an elementary and non elementary function is. My mathematical literacy is quite low. That being said, I feel like I can recognize an elementary function. The definition that I've seen of non-elementary functions on Wikipedia make no sense to me.

Can you give me an example of a non-elementary function? What would taking its derivative or integral look like?

How to Achieve Accurate In-Room Quasi-Anechoic Free-Field Frequency Response Measurements Down to 10 Hz by Jeff Bagby

I have the most recent version of REW (5.20) and all of my on/off axis and far/near field measurements (taken with REW and UMM-6). I'm just wondering if I can do the same thing in REW that Jeff describes with his FRD Response Blender and Minimum Phase Extractor. Bagby's software runs in Excel, but I don't have an active subscription.

Hi, I’m very new to Prolog and because of COVID I’ve received basically no guidance in learning it. I’m also struggling to find recourses online so hopefully someone can help.

I’ve been given the program:

p(0,X,X).

p(s(Y),X,s(Z)) :- p(Y,X,Z).

We were told this used a representation of natural numbers that started with 0 and then used s(n) to represent the successor of n. And then asked to work out which arithmetic function this represents.

I’m still not really sure what it’s for and I can’t get the program to do anything useful despite trying for hours. Any help would really be appreciated.

If you encounter any problems using these exercises, please write about it in the comments.

MultiplicationTableExercises

64 multiplication exercises from 2 * 2 to 9 * 9 presented in random order.

Link to use Multiplication Table Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/MultiplicationTableExercises.html

Link to use Multiplication Table Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/MTEforOldBrowsers.html

AdditionExercises

81 addition exercise from 1 + 1 to 9 + 9 presented in random order.

Link to use Addition Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/AdditionExercises.html

Link to use Addition Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/AEforOldBrowsers.html

SubtractionExercises

45 subtraction exercises from 1 - 1 to 9 - 9, without negative differences, presented in random order.

Link to use Subtraction Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/SubtractionExercises.html

Link to use Subtraction Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/SEforOldBrowsers.html

Versions for older browsers

Versions for older browsers are tested in Internet Explorer 8 and Android Browser of Android 2.3.3

How to use any Exercises offline

• Click Code => Download ZIP
• Extract MultiplicationTableExercises.html or any other .html file from downloaded zip archive
• Open MultiplicationTableExercises.html or any other .html file in your web browser
• Click START button to start exercises
• Click OK button to finish an exercise, or, while input field is selected, press Enter or Numpad Enter on keyboard (in versions for older browsers only clicking OK button may be working to finish an exercise)

Code on GitHub: [https://github.com/Telva

If you encounter any problems using these exercises, please write about it in the comments.

MultiplicationTableExercises

64 multiplication exercises from 2 * 2 to 9 * 9 presented in random order.

Link to use Multiplication Table Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/MultiplicationTableExercises.html

Link to use Multiplication Table Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/MTEforOldBrowsers.html

AdditionExercises

81 addition exercise from 1 + 1 to 9 + 9 presented in random order.

Link to use Addition Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/AdditionExercises.html

Link to use Addition Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/AEforOldBrowsers.html

SubtractionExercises

45 subtraction exercises from 1 - 1 to 9 - 9, without negative differences, presented in random order.

Link to use Subtraction Exercises online:

https://telvannichad.github.io/MultiplicationTableExercises/SubtractionExercises.html

Link to use Subtraction Exercises for old browsers online:

https://telvannichad.github.io/MultiplicationTableExercises/SEforOldBrowsers.html

Versions for older browsers

Versions for older browsers are tested in Internet Explorer 8 and Android Browser of Android 2.3.3

How to use any Exercises offline

• Click Code => Download ZIP
• Extract MultiplicationTableExercises.html or any other .html file from downloaded zip archive
• Open MultiplicationTableExercises.html or any other .html file in your web browser
• Click START button to start exercises
• Click OK button to finish an exercise, or, while input field is selected, press Enter or Numpad Enter on keyboard (in versions for older browsers only clicking OK button may be working to finish an exercise)

Code on GitHub: [https://github.com/Telva