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: Exponential into polynomial

  1. Jul 20, 2010 #1
    1. The problem statement, all variables and given/known data

    Turn y = y(0) * e^(-kt) into a polynomial.

    2. Relevant equations

    3. The attempt at a solution

    I have no idea of how I would go about doing this. I know you can use taylor series to approximate it, but is there any other way?


  2. jcsd
  3. Jul 20, 2010 #2


    User Avatar
    Homework Helper

  4. Jul 20, 2010 #3


    User Avatar
    Science Advisor
    Homework Helper

    Well, no. exp(-kt) isn't a finite degree polynomial in t. You can only approximate it with polynomials. There are other approximations besides taylor series, but I'm not really sure what you are asking.
  5. Jul 20, 2010 #4
    The assignment is to find some value of k given some information, but the assignment wants us to convert that expression into a polynomial then solve for k. Does that make sense?
  6. Jul 20, 2010 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    Take the log of both sides of the equation.
  7. Jul 21, 2010 #6
    Ya i did that, then solved for k but that still doesn't give me a polynomial... :P
  8. Jul 21, 2010 #7


    User Avatar
    Science Advisor

    then perhaps you should tell us what the problem really is- what the "some information" that is given?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook