Real Fuzzy Math


  • 2007 AAR League

    @Jennifer:

    @rjclayton:

    @Jennifer:

    Neutral to most people is better then negative, and thus is good.  Even the number ZERO is considered a positive number (which is why there is not a negative sign on it.)  And before anyone speaks, yes, there is such a thing as -0.  It is approaching zero from the left (ie as the negative numbers increase in value towards zero.)

    Sigh Why do I let myself get sucked into this?

    Actually, zero is neither a negative or a positive number.
    http://mathforum.org/library/drmath/view/58735.html

    This is technically off topic.  I could list an entire library of sources that go into how zero really does have polarity.  But I’ll sum it up pretty and pink:  The link you refrence is a blogger who is attempting to assist grammer and secondary school students and thus, dumbs down the responses to their level.  However, in more esoteric mathematics, you find out that zero really does have a polarity but +0 is equal to -0.  The difference comes into play when you are trying to denote from which direction you are comming from.  It may seem trivial, but the square root of negative one seemed trivial at one time as well.  As did the acceleration due to gravity constant, the speed of light, and all other mathematical break throughs.

    Anyway, long, LONG story short, zero has polarity.  But in fundamanetal mathematics, it’s unneeded and thus, you are told that there is no need to denote the polarity.  After all, at your level of mathematics (you= plural) a zero is a zero.  If you are dividing by it, you have n assymptote.  If you are multiplying by it, you have negated the coefficients and products of that zero.



  • Yeaaaaaaaaaaaa……that is pretty dumb.


  • 2007 AAR League

    @Mechanized:

    Yeaaaaaaaaaaaa……that is pretty dumb.

    :lol:


  • 2018 2017 2016 '11 Moderator

    Dumb or not, it’s true.

    And no, you are not going to debunk millenia of mathematics by quoting some guy with a blog who’s entire goal is to help lesser mathematicians along with rudimentary functions.



  • Yeaaaaaaaaaaaaaaaaaaaaaaaa….

    …its pretty dumb.


  • 2007 AAR League

    How about instead of listing an entire library of resources you could think about just listing one source supporting your argument?


  • 2018 2017 2016 '11 Moderator

    @rjclayton:

    How about instead of listing an entire library of resources you could think about just listing one source supporting your argument?

    I’ll do you one better, I’ll just give you an example.  Otherwise I have to start pulling down math tomes and getting ISBN numbers, then you have to go buy them to check if I am right or not.  (Since the library won’t have them, and I highly doubt you have them, not focusing on theoretical, pure mathematics.)

    Lim f(x)
    X–> 0

    f(x) = (1)/(x)

    Here we have a vertical asymptote.  As you know, you technically cannot divide by zero, but you can approximate.  In this situation you have a result of both positive infinity and negative infinity.  But how do you determine which is really your true answer?  Well, you need to know the polarity of the zero.  Is it positive, or is it negative?  If zero is negative, which means you are approaching from the left, then your answer is negative infinity.  If zero is positive, which means you are approaching from the right, then your answer is positive infinity.

    There are other examples where the polarity of zero is important, but this is one most of you will understand - or so I hope.

    Anyway, this just shows you, just because you don’t know something, does not mean it is wrong.  There are, in fact, many things in theoretical mathematics which are glossed over or simply omitted when instructing younger, less experienced minds so as to avoid confusing them.  Just as first aid glosses over and omitts many medical issues that the first aid student may face, in an effort to insturct without over complicating the issues.


  • 2007 AAR League

    I don’t buy your example.  Sure you can approach 0 from both the -ve or +ve side.  But it would be written like this:

    Lim f(x)
    x -> 0-

    or this

    Lim f(x)
    x -> 0+

    Still doesn’t mean 0 is positive or negative.  Next example please.  Or a souce would still be preferred, as requested.


  • 2018 2017 2016 '11 Moderator

    Phenomenology, Logic and the Philosophy of Mathematics
    Richard Tieszen
    ISBN 0521837820

    Essay #3

    Varieties of Constructive Mathematics
    Douglas S. Bridges, Fred Richman
    ISBN 0521318025

    Lecture Note #79

    How to Read and Do Proofs: An Introduction to Mathematical Thought Processes
    Danial Solow
    ISBN: 0471680583

    Page 179

    Just three I have sitting on my shelf.

    You are correct on your notation, however, you are incorrect as to your interpretation OF ZERO.  Zero is a non-number, it is a placeholder.  While your interpretation would be valid if we were approaching the asymptote at any real number, it is incorrect when we are dealing with Zero.

    Zero is like infinity in that it is very difficult to play with accurately.  It has its own set of rules and regulations.  Now, most of those can be totally ignored when you’re doing something as generic as building a skyscraper, launching a rocket, etc.  However, in pure, theoretical, mathematics - the language of the universe, IMHO - those rules do bear an impact.

    Remember, rules had to be invented to allow you to find real solutions for answers containing the square root of -1, same with division by zero, same with handling answers where literally, the answer is both negative infinity and positive infinity.

    In my, overly simplified, example, you determine which polarity of infinity you are approaching by determining which polarity of zero you are dividing by.  That will tell you from which direction you approach infinity/negative infinity.

    Yes, an instructor would probably tell you with a superscript + or -; but in real mathematics you do not have a professor to just tell you if you approach from the left or the right, you have to determine that yourself.  You can most easily determine that by determining if zero is positive or negative. (did you add to get to zero, then it is negative; did you subtract to get to zero, then it is positive.)



  • Zero is a real number, not a placeholder.
    The set of real numbers includes zero.
    The set of real numbers includes all numbers that are not imaginary (negative square roots)

    Definition of a negative number:
    A number with a value LESS THAN zero

    Definition of a non-negative number:
    A number with a value GREATER THAN OR EQUAL TO zero

    Zero is NOT a negative number since by definition it is non-negative


  • 2007 AAR League

    I don’t understand how negative numbers even exist … they are not a reality they are only created in math.
    You cannot have a negative of something



  • @AJGundam:

    I don’t understand how negative numbers even exist … they are not a reality they are only created in math.
    You cannot have a negative of something

    so all of that debt i had didn’t exist?  What the hell was i working so hard to pay off???



  • Thats perhaps the ONLY time you can use a negative number in the real world……when you are in debt…when you owe someone an amount of something.  Other than that…you cant really have a negative number of anything.



  • temps below freezing are negative numbers
    debt is the use of negative numbers
    elevation below sea level is a negative
    trim plane angles on a submarine can be negative degrees

    Lots of usages in the everyday world…


  • 2007 AAR League

    -Temps below freezing are made up…if you use Kelvin which actually measures from absolute zero you cannot get below 0º
    -Debt shows how much money you owe someone…you don’t actually have negative money
    -elevation below sea level (oxymoron?) is just how far you are below it but putting a negative sign in front of it to show that you are below not above there…you can’t be negative feet above something you are just below it
    -no clue what trim plane angles are



  • Virtually all math is representative.

    My point was only to show where those representations are used in every day life.

    (and trim plane angle is the slope of the fins on a submarine that help the submarine change depth in the water.  A positive trim angle makes the sub rise, a negative angle makes the sub move deeper, unless I have that backward, but you get the idea).


  • 2018 2017 2016 '11 Moderator

    I’m not going to get into a debate about the function of zero with a man who’s highest level of math was maybe Calculus II.  Sorry.  But you just don’t have the ground work to have the debate.  Come back after you take Multilinear Equations and Logic I and II.

    Point is, zero has polarity.  It’s almost always inconsequential, but for every number and placeholder, there is a mirror image of that number or placeholder - even for zero.  It’s just irrellevant until you get to limits, and then it’s limited rellevance and then irrellevant again until you get up to multiple vectors on multiple dimensions/planes.  I’m sure there’s math above me where it’s even MORE rellevant.

    Math, unlike some other areas of study, will never be complete.  There’s always some problem that needs to be fixed, sometimes we do that with imaginary numbers, sometimes with polarity and sometimes with rudimentary and very crude PEMDAS functions.



  • Zero is the absence of value, therefore not positive or negative - just read what Switch said.

    Although, I don’t think there are negative or positive numbers (IMO) - that’s all a point of reference.


  • 2018 2017 2016 '11 Moderator

    @Jermofoot:

    Zero is the absence of value, therefore not positive or negative - just read what Switch said.

    And in lower level math you can negate the polarity of zero, it actually makes lower level math much simpler and easier for beginning mathematicians to understand.  But just because you ignore something does not mean it does not exist.

    For instance, 1/x when x=0 is said to be undefined.  Technically true.  Literally not.  y= infinity and negative infinity at that point and so, since a function cannot have two outputs for one imput, they have to figure out WHY it has two outputs.  The answer?  You had two inputs.  +0 and -0.  But for algebra and trigonometry and calculus I, II and III it’s much simpler to keep the students from being confused and just tell them that the answer is undefined.


  • 2007 AAR League

    I understand what you’re saying, but I thought that issue was solved with limits ie. like in my earlier post:

    lim 1/x = - infinity
    x -> 0-

    lim 1/x = + infinity
    x -> 0+

    when x=0:
    1/(0) = undefined

    So there is actually no value for the function when x=0 (rather than 2 values as you claim).

    Or does higher math undo these teachings and replace with new teachings as you claim?  dun dun dun!


  • 2018 2017 2016 '11 Moderator

    Higher math explains what exactly is happening with limits of undefined results.  It’s less a matter of undoing the teachings as it is expounding on why you were taught that and how to logically arrive at the answer through other, more accurate means.



  • @Jennifer:

    And in lower level math you can negate the polarity of zero, it actually makes lower level math much simpler and easier for beginning mathematicians to understand.  But just because you ignore something does not mean it does not exist.

    I don’t ignore it - there is no polarity of zero.
    A car in reverse has a negative velocity, a car in drive has a positive velocity.  A parked car has no velocity (unless you include it’s velocity on the planet).  It has no polarity because it is nothing.  Plain & simple.

    For instance, 1/x when x=0 is said to be undefined.  Technically true.  Literally not.  y= infinity and negative infinity at that point and so, since a function cannot have two outputs for one imput, they have to figure out WHY it has two outputs.  The answer?  You had two inputs.  +0 and -0.  But for algebra and trigonometry and calculus I, II and III it’s much simpler to keep the students from being confused and just tell them that the answer is undefined.

    f(X) = 1/X IS undefined.  Simply put, X or Y can’t equal zero because 0 /= 1.  There are not two outputs for one input (which IS possible, try f(X) = X2) - just look at the graph!  Zero is absolute - you either have nothing, or you have something.


  • 2018 2017 2016 '11 Moderator

    Jermo, talk to me when you get into higher level math.

    This board does not have support for the appropriate symbology for me to demonstrate just how clueless you are when it comes to pure, logical mathematics.  At very low level calculus and low level physics, yes, you may ignore the polarity of zero.  Sometimes logic dictates that zero has no polarity.  Just like sometimes logic dictates your answer to the question of the velocity of a baseball thrown by a man on planet earth.  Obviously that is going to be bound by 0 < X < 300 miles per hour.  So any answer you get over 300 miles per hour just isn’t going to make mathematical sense for THAT problem.  Does that mean 400 miles per hour does not exist?  Of course not!



  • @Jennifer:

    Jermo, talk to me when you get into higher level math.

    This board does not have support for the appropriate symbology for me to demonstrate just how clueless you are when it comes to pure, logical mathematics.  At very low level calculus and low level physics, yes, you may ignore the polarity of zero.  Sometimes logic dictates that zero has no polarity.  Just like sometimes logic dictates your answer to the question of the velocity of a baseball thrown by a man on planet earth.  Obviously that is going to be bound by 0 < X < 300 miles per hour.  So any answer you get over 300 miles per hour just isn’t going to make mathematical sense for THAT problem.  Does that mean 400 miles per hour does not exist?  Of course not!

    I’m ready to listen, but apparently you aren’t ready to explain it.  What the hell does the baseball velocity have to do with the polarity of zero?
    Here’s a fun one for ya, Jen.
    A negative times a negative = a positive
    A positive times a positive = a positive
    A negative times a positive = a negative
    A positive or negative times zero = ?
    What is it Jen?  I can guarantee you that even if a “positive” or “negative” zero exists, the answer is still the same.


  • 2018 2017 2016 '11 Moderator

    Depends on the rest of the question.  Are you ONLY talking about +0 and -0?

    Which is first?  -0 or +0?  Yes it makes a difference.  I won’t answer until you tell me WHY it makes a difference.  I get paid GOOD money for this information, so I don’t want to give it free to a person who either won’t understand it or won’t appreciate it.


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