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Thread: Slightly advanced math

  1. #1
    SeeDRankLou's Avatar
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    Default Slightly advanced math

    I was in my linear algebra class, and I was taking notes about how to prove Holder's Inequality. There is this one part (noted in red), I don't know how I went from 1 to 2.



    How did I (or my professor) go from 1 to 2?

  2. #2
    FFIX Choco Boy's Avatar
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    Remember Factoring polynomials? Same thing.

    3x^2+7x+2=0
    (3x^2+6x)+(x+2)=0

    Then take out the GCF.
    3x(x+2)+(x+2)=0

    Reduce.
    3x(x+2)=0

    3x=0 x+2=0

    x=0 x=-2

    {-2, 0}

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    One Hundred Chimneys Recognized Member Tavrobel's Avatar
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    Quote Originally Posted by FFIX Choco Boy View Post
    Remember Factoring polynomials? Same thing.
    LOL no. First off, you factored your own example incorrectly.

    3x<sup>2</sup> + 7x + 2 = 0 becomes
    (3x+1)(x+2) = 0
    x = -1/3 and -2

    So that was just plain wrong. Also, I believe you have a severe misconception about what Linear Algebra is. It's Calculus level math, and SRL is working with matrices anyways (at least, that what it appears to be like). I have no idea how he got that 2 coefficient, but try working out the matrices that are given. Maybe a negative somewhere didn't cancel out? When SRL said "slightly," he may have sort of meant "very." It's a joke.

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    I'm selling these fine leather jackets Aerith's Knight's Avatar
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    I think he used Young's inequality to do that step.

    It seems to follow that pattern, although I don't have the time to check it myself, sorry.

    Good luck with the subject. I only scraped by with a 70% on Lineair Algebra myself. ^_^'


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    FFIX Choco Boy's Avatar
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    Quote Originally Posted by Tavrobel View Post
    LOL no. First off, you factored your own example incorrectly.

    3x<sup>2</sup> + 7x + 2 = 0 becomes
    (3x+1)(x+2) = 0
    x = -1/3 and -2
    My mistake, wasn't paying much attention. But, yes, it seems to be the same basic process. I may be misreading some of his notes, because I don't pay a whole lot of attention anyways, but it seems at least very similar.

    Hmm, just looked at it again, yup I looked at it wrong. Disregard and forget.

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    why does american 'math' look so different to english maths?
    I made one myself for a change! Although you can probably tell that..

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    Looks the same as my dutch lineair Algebra, so I think it's just you.


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    SeeDRankLou's Avatar
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    Yeah, it's Young's Inequality. My professor mentioned this in the next class, and then I found where I put this in my notes, it just wasn't given a name. Thanks everyone.

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