maths nerds (important)

Discussion in 'General Discussions' started by SoC, Oct 27, 2009.

  1. SoC

    SoC Moderator
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    1. By direct differentation show that d/dx (ln |x+(x^2-1)^1/2| + constant) = 1/(x^2-1)^1/2 (sorry about the notation, i'll try latex it if people have trouble)

    Attached the other questions in attachment.
    The stars are the ones I need to do.

    I think 5 and 6 i can do, just question 4. Where the hell do I start that?

    As for the first question, I know i have to evaluate the two cases of x and -x and split it up but then what???? Rep on offer :).
     
  2. Zer0

    Zer0 Level IV

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    You sir fail at attaching files XD

    As for number 1, I have no clue what you're rambling on about splitting x and -x.
    Just differentiate using chain rule.

    d/dx [ln|x+(x^2 - 1)^(1/2)| + C]
    = 1/[x+(x^2 - 1)^(1/2)] * [1 + (1/2)*(x^2 - 1)^(-1/2) * (2x)]
    = (1 + x/sqrt(x^2 - 1)) / (x + sqrt(x^2 - 1))

    Then its just algebraic simplification from there.
     
  3. SoC

    SoC Moderator
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    where the hell did that line come from?

    but ah well, I cant be bothered anymore. I'd rather have breakfast than pass my degree B)

    Thanks anyway <3
     
  4. Zer0

    Zer0 Level IV

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    Just algebraic simplification
    x^(-1/2) = 1/sqrt(x)