Results 1 to 5 of 5

Math Help - Log problem.

  1. #1
    Senior Member
    Joined
    Feb 2008
    Posts
    383

    Log problem.

    How to solve \frac{n^2}{2^n} < \frac{1}{1000} ??
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28

    Re: Log problem.

    You can try solving this numerically, I get n\approx 0.03187
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Feb 2008
    Posts
    383

    Re: Log problem.

    is numerically the only way?
    ie not do-able with algebra?

    many thanks.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Behold, the power of SARDINES!
    TheEmptySet's Avatar
    Joined
    Feb 2008
    From
    Yuma, AZ, USA
    Posts
    3,764
    Thanks
    78

    Re: Log problem.

    Quote Originally Posted by BabyMilo View Post
    is numerically the only way?
    ie not do-able with algebra?

    many thanks.
    To do so you will need the Lambert W function Lambert W function - Wikipedia, the free encyclopedia

    Numerically will be your best bet. Here is a start, by algebra we have that

    1000n^2 < 2^n

    \begin{array}{c|c|c}  n & 1000n^2 & 2^n \\  \hline 10 & 100000 & 1024 \\  15 & 225000 & 32768 \\ 20 & 400000 & 1078576 \\ \end{array}

    So we can see the answer is between 15 and 20, just keep going
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member
    Joined
    Feb 2008
    Posts
    383

    Re: Log problem.

    ok thanks.
    I was just wasnt sure whether i could do it algebraically.
    Follow Math Help Forum on Facebook and Google+

Search Tags


/mathhelpforum @mathhelpforum