1. Limited time only! Sign up for a free 30min personal 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!

Simple log question

  1. May 16, 2005 #1
    Help me solve for x in detail please:

    8^x+13^x=108

    Simply done graphically, but algebraically?
     
  2. jcsd
  3. May 16, 2005 #2

    Zurtex

    User Avatar
    Science Advisor
    Homework Helper

    It can't be solved with logs or anything like that.
     
  4. May 16, 2005 #3
    I figured as much after working with it for a while, but I thought I might have just been missing something. How does one solve it then?
     
  5. May 16, 2005 #4

    Zurtex

    User Avatar
    Science Advisor
    Homework Helper

    You can only approximate the solution, which is:

    [tex]x \approx 1.682790571570192534987737142973064792462[/tex]
     
  6. May 16, 2005 #5

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    I think you can't do it,without a calculator.Maple returns [itex] \left\{ x=1.\,68279\,0572\right\} [/itex],but it can't be solved algebraically.In fact,most transcendental equations can't be solved.

    Daniel.
     
  7. Jun 16, 2005 #6
    you can solve it by using newton-raphson method
     
  8. Jun 16, 2005 #7

    Curious3141

    User Avatar
    Homework Helper

    Only approximate, not an exact solution. There is no exact solution method.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Simple log question
  1. Simple Logs (Replies: 7)

  2. A simple log question (Replies: 3)

  3. Simple log question (Replies: 7)

  4. Simple logs question (Replies: 9)

Loading...