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!

Homework Help: A Linear Diet Model

  1. Mar 19, 2006 #1
    I am working on solving a linear diet problem. I am given a differential equation. The problem basically requires me to solve the D.E., then plug 'n chug. I have gone over the solution to the D.E. over and over again. A fellow calculus student has also looked over the math and cannot find the error. Quite possibly there is no error and I am misinterpretting something. I end up with a negative inside of a natural logarithm, but I cannot find a way to get it out. Additionally, I have tried simply using the absolute value of the log, but I don't think this is correct.

    I have put the question along with my work into a PDF file located http://mlowery.t35.com/Special_Project_Weight_Loss.pdf" [Broken]

    If anyone could point out my error/misinterpretation, I would greatly appreciate it.

    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Mar 19, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Why did you call k the initial weight? The initial weight is w(0). (Assuming the initial time is t = 0)
  4. Mar 19, 2006 #3
    Well my new answer seems more logical :)
    Thank you so much Hurkyl.
  5. Mar 20, 2006 #4


    User Avatar
    Science Advisor

    I presume you editted your answer based on what Hurkyl said. I solved the d.e. using a different method but got exactly the answer you did.
    Good work!
  6. Mar 20, 2006 #5
    Yes, I did edit my answer based off of Hurkyl's advice. Thank you HallsofIvy for checking it as well.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook