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: Simple Derivitive

  1. Jan 6, 2007 #1
    It's been a while, but how would you go about deriving

    [tex]y = C e^-^5^x[/tex]

    and plug it into this equation

    [tex]y'' + 4y' - 5y = 0[/tex]

    i can do this without C the answer would be 0, but what do I do with C there?
     
  2. jcsd
  3. Jan 6, 2007 #2

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

    You just differentiate it as usual, leaving the C in front of the terms, and then plug the first and second derivatives into the equation.
     
  4. Jan 6, 2007 #3
    alright thought so, so I should get the same answer if C wasn't there, which is 0

    [tex]25Ce^-^5^x+4(-5Ce^-^5^x)-5Ce^-^5^x = 0[/tex]
     
  5. Jan 6, 2007 #4

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

    Yes, that's correct
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook