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!

Using Graph to determine constants in equation

  1. Jan 23, 2012 #1
    Hello,

    i have the equation F= x + kx^n

    I am trying to determine the constants k and n? where i have the ranges for F and x

    is what i am doing correct?

    log F= logx + logk+ nlogx

    log F= logx(1+n) + logk


    ok i would then plot logF vs Log x. if i am correct logk = y intercept and from that k can be calculated. How would i use the gradient to find the value of n. can someone plz give me some assistance. much appreciated.
     
  2. jcsd
  3. Jan 23, 2012 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member


    No, it is WRONG... log(a+b) is not equal to log(a )+ log(b)

    But log(F-x)=log(kx^n)= logk+n logx.

    Plot out log(F-x) in terms of logx. It has to be a straight line, with y-intercept logk and slope n.

    ehild
     
    Last edited: Jan 23, 2012
  4. Jan 24, 2012 #3
    thank you very much for that correction!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook