1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Logarithm notation question

  1. Jul 19, 2012 #1
    1. The problem statement, all variables and given/known data
    [itex]\left(ln\stackrel{2}{}(1+x)=4\right)[/itex]

    I've never seen a number above the ln like that, usually it's on another term or simply ln(2). What does that numer mean? Is it Log(e)^2 i.e. (Loge)(Loge)? That doesn't make any sense to me.
    2. Relevant equations
    -


    3. The attempt at a solution

    Bring the 2 down and divide both sides by it.
    ln (1+x)=2

    (e^2) - 1=x

    It's supposed to have one more solution, x = (1/(e^2)) - 1
     
  2. jcsd
  3. Jul 19, 2012 #2

    micromass

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    It means

    [itex](ln(1+x))^2=4[/itex]
     
  4. Jul 19, 2012 #3
    Ah that makes complete sense. Thank you.
     
  5. Jul 20, 2012 #4

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Remember that for, any function, f, the notation "f(x)" means the function evaluated at x- that is, f(x) is a number and so [itex]f^n(x)[/itex] is that number to the nth power. Generally, for any function, f, the notation fn means "the value of f to the nth power".

    The only (unfortunate) exception to that is '-1'. [itex]f^{-1}[/itex] typically means "the inverse function", not 1/f.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Logarithm notation question
  1. Logarithm question (Replies: 10)

  2. Logarithm question. (Replies: 11)

  3. Logarithmic question- (Replies: 5)

  4. Logarithms question (Replies: 5)

Loading...