Results 1 to 2 of 2

Math Help - Forgot my Logarithms

  1. #1
    Newbie
    Joined
    Nov 2007
    Posts
    22

    Forgot my Logarithms

    Hello!

    I'm trying to help my niece solve a logarithm problem:

    log(base x) 1/16 = -8

    I'm simply stuck. Here's my process:

    log(base x) 1/16 = -8

    x-8 = 1/16

    x-8 = 16-1

    x-(23) = 2-4

    Is this the right path? Where do I go from here?

    Thank so much!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Dec 2008
    From
    Scotland
    Posts
    901
    Quote Originally Posted by Polyxendi View Post
    Hello!

    I'm trying to help my niece solve a logarithm problem:

    log(base x) 1/16 = -8

    I'm simply stuck. Here's my process:

    log(base x) 1/16 = -8

    xˆ-8 = 1/16

    xˆ-8 = 16ˆ-1

    xˆ-(2ˆ3) = 2ˆ-4

    Is this the right path? Where do I go from here?

    Thank so much!
    If  \log_{a}(b) = c, then a^c = b

    Hence:

    \log_{x} \frac{1}{16} = -8

    Gives:

     \frac{1}{16} = x^{-8}

     \frac{1}{16} = \frac{1}{x^8}

     x^8 = 16

     x = \pm (16)^{\frac{1}{8}}

     x = \pm ((16)^{\frac{1}{2}})^{\frac{1}{4}}

     x = \pm (4)^{\frac{1}{4}}

     x = \pm ((4)^{\frac{1}{2}})^{\frac{1}{2}}

     x = \pm (2)^{\frac{1}{2}}

     x = \pm \sqrt{2}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Forgot how to do this and need help :)
    Posted in the Geometry Forum
    Replies: 1
    Last Post: May 31st 2011, 02:46 AM
  2. Replies: 0
    Last Post: March 10th 2010, 07:24 AM
  3. I forgot how to do this...help.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: December 16th 2009, 12:29 PM
  4. Forgot
    Posted in the Algebra Forum
    Replies: 5
    Last Post: August 20th 2009, 11:39 PM
  5. some how forgot
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 27th 2009, 04:37 AM

Search Tags


/mathhelpforum @mathhelpforum