Results 1 to 4 of 4

Math Help - Perhaps a simple log problem here..but Im quite stuck

  1. #1
    Junior Member
    Joined
    Dec 2009
    Posts
    29

    Perhaps a simple log problem here..but Im quite stuck

    Im quite stuck on starting this problem. I feel totally useles at doing all show that questions, unfortunately they are the hardest question for me and this is no different:

    Given that Log_a x= 2log_a 6 - log_a 3, show that x=12
    Do I assume that log_a is log _{10}?

    Im am actually very stuck, so any help would be greately appreciated kind people

    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Anonymous1's Avatar
    Joined
    Nov 2009
    From
    Big Red, NY
    Posts
    517
    Thanks
    1
    Quote Originally Posted by fishkeeper View Post
    Do I assume that log_a is log _{10}?

    \text{\color{red}{no.}}
    log_a x= 2log_a 6 - log_a 3

    \Rightarrow log_a x= log_a (6)^2 - log_a 3

    \Rightarrow log_a x= log_a \frac{(6)^2}{3} = log_a 12

    \Rightarrow a^{log_a x} = a^{log_a 12}

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

  3. #3
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,695
    Thanks
    450
    Quote Originally Posted by fishkeeper View Post
    Im quite stuck on starting this problem. I feel totally useles at doing all show that questions, unfortunately they are the hardest question for me and this is no different:

    Do I assume that log_a is log _{10}?

    it doesn't make a difference.
    this is just an exercise in the properties of logs

    \log{x} = 2\log{6} - \log{3}

    \log{x} = \log{6^2} - \log{3}<br />

    \log{x} = \log{36} - \log{3}

    \log{x} = \log\left(\frac{36}{3}\right)

    \log{x} = \log{12}

    x = 12
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Dec 2009
    Posts
    29
    Thankyou both for taking the time to answer the question.

    Now Ive seen the answer in front of me, it seems so simple
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 5
    Last Post: May 31st 2011, 04:01 PM
  2. Stuck on simple calculus problem...
    Posted in the Calculus Forum
    Replies: 6
    Last Post: November 27th 2010, 06:19 PM
  3. I'm stuck with simple DE
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: April 11th 2010, 12:06 PM
  4. Stuck on super-simple complex problem
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: February 24th 2010, 01:20 PM
  5. Simple Isolation Problem. Stuck.
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 18th 2008, 11:27 AM

Search Tags


/mathhelpforum @mathhelpforum