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Math Help - Problem with exponential question

  1. #1
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    Exclamation Problem with exponential question

    Given that lnx =1.5 and ln√y =2.2 , evaluate

    (i)


    (ii) 2x-y


    The answer given is (i) 0.781 but i cant seem to get it.

    For part (ii), im not sure how to even start.
    Could somebody help me with this?

    Thank you very much!
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  2. #2
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    Re: Problem with exponential question

    Quote Originally Posted by pumbaa213 View Post
    Given that lnx =1.5 and ln√y =2.2 , evaluate
    (i)


    (ii) 2x-y
    \sqrt{\ln(ex)}=\sqrt{\ln(e)+\ln(x)}=\sqrt{2.5} Do you know why?

    \ln(y)=4.4 Do you know why?
    Thanks from pumbaa213 and topsquark
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  3. #3
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    Re: Problem with exponential question

    Okay i got the first part thanks alot! its so much easier when someone dissects it for you.
    How about (ii) 2x - y

    How should i start?

    thank you!
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  4. #4
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    Re: Problem with exponential question

    You could start by putting x and y in simple terms. So:

    lnx=1.5 \textup{ so }x=e^{1.5}

    ln\sqrt{y}=2.2

    ln(y^{\frac{1}{2}})=2.2

    \frac{1}{2}lny=2.2 \textup{ so }y=e^{4.4}
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  5. #5
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    Re: Problem with exponential question

    yess! finally got the answer. Thank you plato and grillage!
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