Results 1 to 2 of 2

Math Help - Help me with log. tmr exam!

  1. March 25th 2009, 12:15 AM #1
    helloying
    helloying is offline
    Member helloying's Avatar
    Joined
    Jul 2008
    Posts
    177

    Help me with log. tmr exam!

    lgx+ln2x=3
    solve the eqn
    thanks
    Follow Math Help Forum on Facebook and Google+
  2. March 25th 2009, 03:54 AM #2
    Grandad
    Grandad is offline
    MHF Contributor
    Grandad's Avatar
    Joined
    Dec 2008
    From
    South Coast of England
    Posts
    2,570
    Thanks
    1

    Logs

    Hello helloying
    Quote Originally Posted by helloying View Post
    lgx+ln2x=3
    solve the eqn
    thanks
    I assume that lgx means \log_{10}x and ln2x means \log_e2x (= \log_e2 + \log_ex).

    In which case, you need to know that \log_{10}x = \frac{\log_ex}{\log_e10}. So the equation becomes:

    \frac{\log_ex}{\log_e10} + \log_e2 + \log_ex = 3

    \Rightarrow \log_ex\left(\frac{1}{\log_e10} + 1\right)= 3 - \log_e2

    Can you finish it from here?

    Grandad
    Follow Math Help Forum on Facebook and Google+
« [SOLVED] Simultaneous Exponential Equations Problem | Algebra + fractions »

Similar Math Help Forum Discussions

  1. 2nd PDE for Exam
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: September 13th 2010, 03:43 PM
  2. PDE for Exam
    Posted in the Differential Equations Forum
    Replies: 4
    Last Post: September 13th 2010, 11:49 AM
  3. Help for exam
    Posted in the Statistics Forum
    Replies: 0
    Last Post: June 8th 2010, 08:41 AM
  4. exam help
    Posted in the Algebra Forum
    Replies: 6
    Last Post: March 15th 2010, 02:10 AM
  5. exam help
    Posted in the Algebra Forum
    Replies: 1
    Last Post: December 13th 2009, 10:33 AM

Search Tags


/mathhelpforum @mathhelpforum