#Inverse proportional?
255 messages · Page 1 of 1 (latest)
I've never seen notation like this. Can you provide context?
yes I have to search
OK someone said that it is best to think of fractions like this. Does that make sense with the formula?
Oh. Then it's just division, I guess.
ok it's an inversion of multiplication
Yeah, definitely division, then.
rockhoven
It's just a/b.
someone said to think of fractions like this
ok
because I want to think of 2/3 like this
but I would think it easier to just invert to 3/2
I think the point of this is to show that a/b = ab^(-1).
Well in terms of algebraic structure that’s how division should be defined a x b^-1 =a/b the right side of the equality is a notation
( if b is nonzero of course so it’s invertible)
As usual, power.
That's just a basic property of powers: 1/b = b^(-1).
It’s a definition if you are in a ring ( or field in this case) the inverse of b (if invertible) is written b^-1
in whole number math a smaller number is not divisible by a larger number
that's all i know is whole number math
the poster said it is best to think of fractions in this form
$a\times^{-1}b$
rockhoven
So how would we think of 2/3?
If you are writing « 2/3 » you aren’t doing arithmetic if that’s what you mean we are in (R,+,x) which is a field and 2/3 is actually 2 x 3^-1 ( 1/3 is the inverse of 3)
so it is an inverse proportion?
Well if you define X^-1 :(a,b)—> a X^-1 b=a x b^-1 then I guess yes
2/3 is actually 2 x 3^-1
you are pulling my leg now?
X^-1 :(a,b)—> a X^-1 b=a x b^-1
what is that?
2/3?
well that second one is a general statement?
2/3 is actually 2 x 3^-1
?
why is it necessary to use a power?
They are the same yes
Yes
b^-1=1/b
( for a non zero b )
I guess yes
because 0/1 iand 1/0 are not inverse proportionals?
ok
then why not just say "inverse proportional"?
That just looks like a "proportional" sign. It doesn't make much sense, though.
Maybe you meant (2/3)^(-1) = 3/2?
Why would we use it when talking about just numbers?
Proportionality is useful when talking about variables, not just numbers.
we have the same idea but it's another vocabulary
ok
I don't know very much
but the poster said that it's best to think of fractions using this formula
i don't know why it would be any more beneficial over just saying "inverse proportional"
or using ∝
fractions consist of numbers
so that is the context
In middle school, I guess.
only classical math
Well, this is arithmetics, which has been around for thousands of years...
whole number math in which 1 is indivisible
not quite
there is a difference in classical thinking about numbers
What exactly do you mean by "classical"?
pre modern
at some point 1 became dividible
no clear line of demarcation
in plato's and euclid's time 1 was indivisible
it makes for some controversy
Wait, you mean you started learning mathematics by reading ancient texts?
yes
Uhh... well, I mean, they are interesting, sure. But I don't think that's a good idea.
I mean, this is just arithmetics. This is what you learn in middle school.
Doesn't matter whether you want to be a mathematician or not, everyone learns this.
I didn't go to school
Wait, what?
But that means you did go to school.
If you're in 8th grade, this should all be familiar to you from long ago.
I went to a college and looked at it and left
so i went to college
$a\times^{-1}b$
rockhoven
anyway someone else is telling me that this is meaningless
Well, this just means that division and multiplication are inverse operations.
Noone really writes it like this, of course.
but you just said that
and i understnd that
i could hhave told you that
it must be some conventional shorthand for the phrase
it's needed for doing more than just fractions
variables
so this sort of has something to do with inverse proportionals but not necessarily so?
can it be used any other way
Sorry, but I have no idea what you're talking about.
how would it be different if we were using variables
it would still represent an inverse realtion
But we are using variables here: a and b.
That can only be true if a/b = ±1. Can't be true in general.
ok
a is similar to b
No, I mean that a is proportional to b.
I shoud hope so
if they have square relation they are similar
both the sides and the areas are proportional
Variables can be proportional, not similar. Shapes can be similar.
I don't understand anything you wrote there
why did you make a discussion post about this
ok i accept that this notation may have been a goofy step off the beaten path that confused everyone
i was indeed just trying to say that a fraction is something that undoes multiplication
Fr il quite confused tbh
in a way that does not use the concept of an inverse element
Sorry, but I don't understand what you're talking about, either.
all math confuses me
I think we should go back to using an indivisible 1
***i was indeed just trying to say that a fraction is something that undoes multiplication
I understand that
but I learned that by working with inverse proportionals
great good for you
guess i have to be careful in the future not to say anything that might trigger anyone to unleash another discussion post on this poor forum
I don't think there's any problem
I'm doing fine
I love it
It's great
We are here to have a good time and pick up a bit of knowledge here and there
If there is no inverse element then what is happening here? I just want to know the ideas behind the maths.
I don't think that we can disassociate math from prose
Since math is a language, there has to be explanations for what is said
Einstein writes in prose while introducing his formulas and equations
The symbols of math are symbols for ideas
The underlying ideas are what matters
once we agree upon the ideas then mathematical symbols can be applied
for example
in this conversation we could represent my whole last sentence by the letter a
the a is all I have to write in order to express that statement
a = "once we agree upon the ideas then mathematical symbols can be applied"
The main reason for using one letter is to abbreviate waht we are saying
instead of writing out 10 or 12 words every time we wanted to refer to our topic we could just write one letter a
but it is the ideas that matter here
maybe you will counter and say that is logic, not math
let b = "I'll have some pumkin pie"
what is a/b?
"once we agree upon the ideas then mathematical symbols can be applied" / "I'll have some pumkin pie" ?
This does not make any sense
and the reason is that these two things are not homogenous
you can't divide mathemtical symbols by pumkin pie
they are heterogeneous terms
and substances
Let Q.E.D = So There!
Q.E.D.
I am trying to be as agreeable as I can be. I just want clarity. Nothing is expressed poorly if we can agree upon it. I just want to know what it means before I sign on to.it. I uncritically accpted 1 + 1 = 2 when I was 6 years old and I shouldn't have. "i was indeed just trying to say that a fraction is something that undoes multiplication" OK. So I'll agree to the that. That is something I have continued to learn by working with inverse proportionals. I'm just wondering how I can understand and utilize this formula. That depends on whetehr I can input numbers and get the desired outputs. Your formula need only be tested and possibly refined. I wouldn't know. I am not a mathematician. Most of us here are dummies. Run some tests on your formula and give us some demonstrations that we can understand. I don't think that you have made any misstep in attempting to formulate a thought. All ask is that you continue.
The main reason for using variables is abstraction. For example, consier the sentances "x + y = y + x for all real numbers x and y" or "f(x) = x^2 + 2 for all integers x".
I think that you may be underestimating your intuitions. Why can we not think of 2/3 as -6?
When fishing for an idea, you wrote something. Now you think it's goofy?
That is usually the sign of intuition. You may have had a bunch of math lurking around in your brain.
and it spontaneously erupted. Such thought are initially going to appear ridiculous to you conscious mind
however you may just be on the right track
I reward you with a song. Keep the ideas coming
Why can't we thinkof 2/3 as -6. What other number could we expect to come out of the formula? A prime? 11? No. I would expect 6 to come out because 2 and 3 went into the forumla. I think it is also an inverse proportional because it carries a negative sign, it produced -6. I really think you may have hit upon something. All we haev to do now is give the formula some extra meaning which elucidates the thought processes.
Now, -6*6=-36
6 has to be able to represent 2/3 because we set up the internal structure of the number to be so. There undoubtedly is a relation between 2/3 and 6.
Now inverse ratios look like this: 3:2 ∝ 2:3 and such a relation generates squares which is what has occurred here. for the extremes of this proportion are square 3x3 and the means are square 2x2 which gives a square relation of 4 to 9. 4 and 9 are factors of 36. Your equation spits out -6 and -6x6=-36, yet another square. -6 and 6 must be representative of our original inverse ratio of 3:2 ∝ 2:3 .
The fact that the relations are square numbers indicates an inverse proportional.
But I am even more interested in the intuitive processes that brought this to your mind and those intuitive processes that led me to a recognition of your genius.
I said before that I sometimes played with relations (ratios) of two or more numbers in my mind. Just very low numbers and elementary mathematical thinking. I more than once noticed that if I played with these number long enough I ended up with whole numbers. Your formula renders whole numbers. You also said in introducing the formula that this is the way to think about fractions. I intuitively agree with you but I don't yet know why. That is why I am instigating a full review of your formula to find out what makes it work and how we thought this thing up together directly from the subconscious materials of math.
Remember - it's the thought that matters
Now how did you think up this formula? Surely it has some history?
You know it just dawns on me that we are all saying the same thing no matter the language of math that we speak, no matter what your equations are or how you write them, we are all talking about proportion
that's it
that's really all there is to the math business
proportionals
all of this different math that you and I do or don't understand is about proportionals
when you talk about Maxwell's spectrum or Pascal's triangle or a Fouier series
it's all about proportion
trig calc all of it
I mean I don't know that stuff but that is my guess
I want to say this because there may be some confusions in the way we are communicating
but we are all talking about this same thing in different ways
what the formula in the OP comes down to is proportion
because it was admitted to express a proportion, namely, a fraction
I put a ratio into
all that could come out of it was a ratio or a proportion
because that is what I put into it
so the output of -6 from the forumla must simply be accepted and understood as expressing a proportion
I put 2/3 into it
why should any number other than 6 come out of it?
-6 is just an inverse relation
Well in a mathematical group the inverse of an element b is denoted b^-1 so if you consider (R,+) it’s a group and « 3^-1 » is « -3 » for that group but that’s a notation when we write 2/3 we of course are referring to the inverse of multiplication and not the inverse of addition because that’s just the way it was created and it makes sense
Saying 2/3=-6 can make sense if you really stretch it like this but it’s a notation
It’s like saying a cat and a dog are the same because both have four legs both have the same « property » they have both four legs ( in this case both are inverse in their respective sets, so group and field respectively) but that doesn’t mean they are the same that makes no sense
My example is very bad but I hope it makes sense
If my grandmother had wheels she would be a bike
Well that applies to cyclic groups as well lol
That was bad
My bad
yer grandmother does have wheels. She also wears army boots.
LOL
OK. I think that I don't understand the vocabulary of modern math very well. If you explain your ideas and the notation I can catch on to it. Like your talking about group theory. OK I have probably been exposed to the concepts but just don't have the vocab for it.Like you wrote all of these symbols. If I understood the symbols I don't think the ideas would be a problem
but yes when I did stumble upon a whole number while thinking of fractions or comparisons of number or proportional, I did scratch my head and wonder how I arrived at a whole number. I know that saying that 6 can represent 2/3 may seem odd and it seemed odd to me then
but I was wondering if an formula like this, if explored, could reveal what those thought processes were because if those processes are beneficial I would want to continue explorations there and if not I would want to be able to instantly recognize them and eliminate them.
I am just wonding if this formula might be useful
I rather like the idea of a whole number representing a relation between two numers
because it's a crazy idea and I am not shy at all about handling strange ideas
Einstein handled weird ideas for his time
I am now obsessed with this formula and these ideas
How about $a +^{-1} b$? Or would it be $a (-1)+ b$?
Djake3tooth