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a log question from p2 watch

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    here is the question: (the q in bold is the base)

    given that p=log q16 express in terms of p,

    (a) log q2
    (b) log q(8q)


    for (a) i got the answer as p/4 but i cant remember how to solve (b).
    hope someone can help
    cheers
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    think rules of logs for a
    a) since 2^4=16 it's 1/4p
    b)*all in base q) log8q=(LN8/LN16)p
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    i am sorry but i still do not understand how to solve (b). could u possibly expain a bit more. it is a 4 mark question
    thanks
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    (Original post by theunforgiven)
    i am sorry but i still do not understand how to solve (b). could u possibly expain a bit more. it is a 4 mark question
    thanks
    erm lets see even this is the right solution. as far as i recall it's much simpler than this but lets have a look.
    p=logq of 16.
    y=logq of 8q

    I don't like logq so i make p=LN16/LNq
    where q=16/p
    =>y=logq of 128/p,
    which means
    logq of 128-logq of p
    and p was from above log base q of 16, so substituting it back in

    and since logq of 128 is 7/4p then you have
    7/4p-logq of p, which i leave to you to solve.

    It's such a pitty latex isn't working, or i would have written it out neatly. I'm hoping this is right.
 
 
 
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Updated: February 5, 2006

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