Results 1 to 6 of 6

Math Help - Solving problems with natural logs

  1. #1
    Junior Member
    Joined
    Nov 2010
    From
    Colorado
    Posts
    42
    Thanks
    2

    Solving problems with natural logs

    \ln(x^2)=10

    I know how to solve this by turning it into an exponential form ie.

    e^{10}=x^2

    and solving from there but can you do something like this

    e^{\ln(x^2)}=e^{10}

    e^{2\ln(x)}=e^{10}

    I don't know what to do from here.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Oct 2012
    From
    Ireland
    Posts
    607
    Thanks
    168

    Re: Solving problems with natural logs

    If e^{2\ln(x)}=e^{10} You can put their indexes equal to each other so 2ln(x)=10
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Nov 2010
    From
    Colorado
    Posts
    42
    Thanks
    2

    Re: Solving problems with natural logs

    Where would I go from there? Does that get me any closer to solving for x? Sorry if I'm missing what you are getting at.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    Joined
    Oct 2012
    From
    Ireland
    Posts
    607
    Thanks
    168

    Re: Solving problems with natural logs

    From 2ln(x)=10 you can continue
    ln(x)=5
    x=e^5

    And you get the same answer as your first method
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Nov 2010
    From
    Colorado
    Posts
    42
    Thanks
    2

    Re: Solving problems with natural logs

    Ah, I see. Apparently I'm a little rusty at this stuff. Thanks for the help.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Junior Member ReneG's Avatar
    Joined
    Mar 2013
    From
    United States
    Posts
    70
    Thanks
    9

    Re: Solving problems with natural logs

    You should brush up on your log properties.

    \log_b{a^n} = n \log_b{a} would have saved you time
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 9
    Last Post: February 22nd 2011, 06:39 PM
  2. Replies: 6
    Last Post: March 18th 2009, 05:10 AM
  3. solving for t with natural logs
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 24th 2009, 09:50 PM
  4. Dealing with Logs and Natural Logs
    Posted in the Advanced Algebra Forum
    Replies: 0
    Last Post: April 14th 2008, 07:18 AM
  5. several questions-logs/natural logs
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: November 12th 2007, 09:58 PM

Search Tags


/mathhelpforum @mathhelpforum