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    Hey, I was wondering if someone could help me with this question. The answer to part (i) is k=4

    In the second part i got 4/2root2 but the mark scheme says that it is wrong. In the mark scheme they change infinity to 4, but why?
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    What is the answer on the MS?
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    (Original post by Appazap)

    Hey, I was wondering if someone could help me with this question. The answer to part (i) is k=4

    In the second part i got 4/2root2 but the mark scheme says that it is wrong. In the mark scheme they change infinity to 4, but why?
    If you mean you got \dfrac{4}{2\sqrt{2}} then this is fine because it is equal to \sqrt{2} which is the answer.

    As for why they change to 4, I don't know. Post the mark scheme.
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    (Original post by TheTechnocrat)
    What is the answer on the MS?
    just root 2
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    I think it is most likely a misprinted
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    (Original post by Appazap)
    just root 2
    You just need to rationalise the denominator.
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    (Original post by RDKGames)
    If you mean you got \dfrac{4}{2\sqrt{2}} then this is fine because it is equal to \sqrt{2} which is the answer.

    As for why they change to 4, I don't know. Post the mark scheme.
    oh i feel like an idiot!! have they they just rationalised the denominator then?


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    (Original post by Appazap)
    oh i feel like an idiot!! have they they just rationalised the denominator then?


    also mark scheme Name:  Ugfurdytntitled.png
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    Yes.
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    (Original post by Appazap)
    oh i feel like an idiot!! have they they just rationalised the denominator then?


    also mark scheme
    Yes they rationalised the denominator.

    What they do in MS is they turn the integral into a proper one with a limit of k (which has a different value than in the prev part), then they evaluate the integral in terms of k, then they see what the limit of it is when k \rightarrow \infty.
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    (Original post by TheTechnocrat)
    Yes.
    (Original post by RDKGames)
    Yes they rationalised the denominator.

    What they do in MS is they turn the integral into a proper one with a limit of k (which has a different value than in the prev part), then they evaluate the integral in terms of k, then they see what the limit of it is when k \rightarrow \infty.
    Thank you all!!
 
 
 
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