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: Discrete Math: Functions with Powers

  1. Dec 5, 2011 #1
    Did this as a hw problem, got it wrong obviously. Not too sure how to solve it otherwise

    1. The problem statement, all variables and given/known data
    Let f be a function from A to A. Prove that for all m,n ε N, f^m*f^n = f^(m+N)


    2. Relevant equations



    3. The attempt at a solution

    f^(m+1) f^(n+1) = f(f^m) * f(f^n)
    = f(f^m * f^n) <--- this I think is what I did wrong
    = f(f^(m+n)) since a^m * a^n = a^(m+n)
    = f^(m+n+1)
    = f^(x+1) where x = m+n
     
  2. jcsd
  3. Dec 5, 2011 #2
    Can't find edit button:
    Found an error.. it should say
    1. The problem statement, all variables and given/known data
    Let f be a function from A to A. Prove that for all m,n ε N, f^m*f^n = f^(m+n)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook