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: Giving a Recursive Formula

  1. Mar 10, 2008 #1
    [SOLVED] Giving a Recursive Formula

    1. The problem statement, all variables and given/known data
    Give a recursive definition of
    a) the set of odd positive integers.
    b) the set of positive integer powers of 3.
    c) the set of polynomials with integer coefficients.

    I've solved a).
    Having trouble with b).
    Unsure what c) is asking.

    For a), got: f(0) = 1, and f(n) = f(n – 1) + 2.
  2. jcsd
  3. Mar 10, 2008 #2

    Gib Z

    User Avatar
    Homework Helper

    For b), I'm sure you could tell me what f(0) is? f(1) would be how many times f(0)? What if you repeat this process?
  4. Mar 10, 2008 #3
    Ahhh, now that I've slept, I see I misread the question.
    It is saying 3^n, not n^3.

    This makes it much easier. For n^3, I'd have to cuberoot, add 1, and cube to get to the next step, which felt like "cheating", for some reason. 3^n will be much easier.

    Still unclear on what c) is referring to.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook