Results 1 to 3 of 3

Math Help - Natural Logs/ Logarithms?

  1. #1
    Member
    Joined
    Jul 2010
    Posts
    109

    Exclamation Natural Logs/ Logarithms?

    Hi!
    I am taking AP Calc AB and my new teacher sent us a math assignment to do over the summer.

    There is this question that stumped me.

    Evaluate or simplify

    a. ln Ce^-at

    I have never seen something like this in my life! I tried googling it but no answer. Obviously it has something to do with logarithms and natural logs because of the "ln". How would I simplify/evaluate?

    Just to check my work for letter b the problem is:

    log4 (1/8)

    that would be 4^x= 1/8 right?

    Thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Also sprach Zarathustra's Avatar
    Joined
    Dec 2009
    From
    Russia
    Posts
    1,506
    Thanks
    1
    a. ln Ce^-at


    ln a^b=b ln a

    ln Ce^-at = -at ln Ce

    ln(a * b) =ln a + ln b


    ln Ce^-at = -at ln Ce = -at(lnC + ln e)

    ln e=1

    ln Ce^-at = -at ln Ce = -at(lnC + ln e)=-at(lnC+1)
    Follow Math Help Forum on Facebook and Google+

  3. #3
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2
    Are C and e different symbols? Could you please clarify with parentheses?
    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. Natural Logarithms
    Posted in the Calculus Forum
    Replies: 2
    Last Post: December 3rd 2008, 12:01 PM
  3. Dealing with Logs and Natural Logs
    Posted in the Advanced Algebra Forum
    Replies: 0
    Last Post: April 14th 2008, 07:18 AM
  4. Natural Logarithms Help Plz!
    Posted in the Pre-Calculus Forum
    Replies: 9
    Last Post: February 26th 2008, 02:14 PM
  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