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  1. #241
    W. Rabbit's Avatar
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    One sec....post fail..

  2. #242
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    Hell yeah! Hell no!
    Is this algebra or is it just arithmetic?

  3. #243
    W. Rabbit's Avatar
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    Quote Originally Posted by goodlun View Post
    Interesting point, so why did the CAS in the Ti-89 and Wolfalpha miss this?
    Because of the distributive properties
    6/2(2+1)==6/(4+2)
    6/6
    Parenthesis are not supposed to be the same as multiplication (e.g. 2*x and 2(x) are not technically the same, 2(x) is supposed to be a higher order operation).

    But there is more to it than that...generational differences in calculators, for one. This is truly a math geek's sort of thing, so it makes me sick to my stomach and I need walk away and chew on some beef jerky.

    Read away:

    Date: 05/02/2008 at 13:20:22
    From: Doctor Peterson
    Subject: Re: Multiplying parenthetical phrases and order of operations

    Hi, Rob.

    Your two expressions in the calculator are

    36 / 6 ( 25 - 11 * 2 )

    and

    36 / 6 * ( 25 - 11 * 2 )

    The problem is that some calculators that allow multiplications to be implied as in the former case treat that as a higher precedence operation (as some algebra texts say), while others treat all multiplications alike (as most texts do, in my experience). You can read a little about that here:

    Order of Operations
    http://mathforum.org/library/drmath/view/54341.html

    That has a bad link to TI's site; a current version can be found by going to their Knowledge Base and searching for "implied
    multiplication". Here is a quote:

    Solution 11773: Implied Multiplication Versus Explicit
    Multiplication on TI Graphing Calculators.


    Does implied multiplication and explicit multiplication have the
    same precedence on TI graphing calculators?

    Implied multiplication has a higher priority than explicit
    multiplication to allow users to enter expressions, in the same
    manner as they would be written. For example, the TI-80, TI-81,
    TI-82, and TI-85 evaluate 1/2X as 1/(2*X), while other products
    may evaluate the same expression as 1/2*X from left to right.
    Without this feature, it would be necessary to group 2X in
    parentheses, something that is typically not done when writing
    the expression on paper.

    This order of precedence was changed for the TI-83 family, TI-84 Plus family, TI-89 family, TI-92 Plus, Voyage™ 200 and the
    TI-Nspire™ Handheld in TI-84 Plus Mode. Implied and explicit
    multiplication are given the same priority.


    If you have any further questions, feel free to write back.


    - Doctor Peterson, The Math Forum
    http://mathforum.org/dr.math/
    Last edited by W. Rabbit; 11/08/2012 11:03pm at .

  4. #244
    Tranquil Suit's Avatar
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    Damn, giving imlicit multiplication a higher priority just for the sake of (dubious) convenience is retarded. No wonder kids were screwed up in the 90s.


    Quote Originally Posted by W. Rabbit View Post
    The reason the answer is 1 is because there are two parenthesis operations in the original, not one.

    6/2(2+1) = 6 / 2(3) = 1

    is not

    6/2*(2+1) = 9
    I first thought you were trolling. Parentheses are not operations! Yes, they state explicit order of operations, but they themselves are not operations.

    ****, I'm almost screaming this out loud.
    Last edited by Tranquil Suit; 11/09/2012 1:32am at .
    go to http://www.bullshido.net/forums/prof...do=editoptions > under Thread Display Options > Number of Posts to Show Per Page: 40

  5. #245
    W. Rabbit's Avatar
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    Quote Originally Posted by Tranquil Suit View Post
    I first thought you were trolling. Parentheses are not operations! Yes, they state explicit order of operations, but they themselves are not operations.

    ****, I'm almost screaming this out loud.
    I was referring to PEMDAS operations, not formal algebraic ones.

  6. #246
    Tranquil Suit's Avatar
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    Yes and still I'm going :Rage2:



    Damn. Out of all the things on Bullshido, this is what gets me.
    go to http://www.bullshido.net/forums/prof...do=editoptions > under Thread Display Options > Number of Posts to Show Per Page: 40

  7. #247
    W. Rabbit's Avatar
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    Quote Originally Posted by Tranquil Suit View Post
    Yes and still I'm going :Rage2:

    Damn. Out of all the things on Bullshido, this is what gets me.
    What's that? Time to switch topic?

    Let's talk about the new dinosaur named after Sauron!

    Last edited by W. Rabbit; 11/09/2012 2:02am at .

  8. #248
    goodlun's Avatar
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    I am actually kicking myself pretty hard for fucking this up. I have gone all the way through calc3. I do math on a fairly regular basis as a professional need.
    I am actually rather embarrassed in fact it sort of kind of depressed me quite a bit earlier.
    No matter how much I want the answer to be 1 so that I will be right there is nothing I can do about it because
    the answer is
    9

    I also get the frustration your having, people fucking up hard factual things is scream worthy as there is no grey area.

  9. #249
    W. Rabbit's Avatar
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    Quote Originally Posted by goodlun View Post
    I am actually kicking myself pretty hard for fucking this up. I have gone all the way through calc3. I do math on a fairly regular basis as a professional need.
    I am actually rather embarrassed in fact it sort of kind of depressed me quite a bit earlier.
    No matter how much I want the answer to be 1 so that I will be right there is nothing I can do about it because
    the answer is
    9

    I also get the frustration your having, people fucking up hard factual things is scream worthy as there is no grey area.
    No, the "answer" is not 9, or 1. It can be either. Read what I sourced above. There is a reason hundreds of smart people can "prove it" both ways and why different brands of calculator show it both ways.

    The "answer" depends on what you're trying to use the notation to solve. And yes, adding explicit parenthesis clears it all up for the computer as Rivington pointed out.

    Quote Originally Posted by goodlun View Post
    I also get the frustration your having, people fucking up hard factual things is scream worthy as there is no grey area.
    People fucking up your and you're bugs me too, man. I feel you.

    :Rage2:
    Last edited by W. Rabbit; 11/09/2012 2:16am at .

  10. #250
    goodlun's Avatar
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    Quote Originally Posted by W. Rabbit View Post
    The "answer" depends on what you're trying to use the notation to solve. And yes, adding explicit parenthesis clears it all up for the computer as Rivington pointed out.
    The original problem didn't have the extra set of parenthesis, adding them changes the problem and the answer at that point is 1. There is no special way of using the notation, the notation is what it is. This didn't come from a word problem. Its a typical here are some numbers put down in an order solve them sorts of thing. When you follow the PE MD AS rules the answer comes out to 9.

    Quote Originally Posted by W. Rabbit View Post

    People fucking up your and you're bugs me too, man. I feel you.

    :Rage2:
    Yep its a mistake I make, I understand the difference and when I am being careful I don't make it. When I am just writing a quick retort your going to get all sorts of there their, your, you're, and **** it pretty much this
    http://theoatmeal.com/comics/misspelling
    I should be more careful as to be taken more seriously but what eves

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