Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Exponential and logarithmic properties

  1. May 19, 2006 #1
    Hi. I'm having trouble solving for t:

    1180 = 98t + 1080e^(-t/10)

    I know basic properties but I think I am not remembering some idea or specific property to be able to solve this. Thank you for any help.
  2. jcsd
  3. May 19, 2006 #2


    User Avatar
    Science Advisor

    Since the variable, t, appears both "inside" an exponential and "outside" there is no elementary function that will reduce that equation. You might look at "Lambert's W function" (check
    http://en.wikipedia.org/wiki/Lambert's_W_function) which is defined[\b] as the inverse of the function f(x)= xex.
    A variation of that will "solve" your equation.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook