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!

Limit prove

  1. Aug 15, 2009 #1
    Hi,I have no idea on how to begin with this question.The question is:

    Prove that (n+a)!/(n+b)! ~ na-b as n goes to infinity.There are clue given that we can use Euler's limit and Stirling's formula to solve this question.Can you please give me some hints on how to start with this question?

  2. jcsd
  3. Aug 15, 2009 #2
    I don't think any advanced machinery is necessary here. For any n, the term n!/n! = 1 can be ignored so we have left only a factors containing n in the numerator and b factors containing n in the denominator. You can then either note the polynomial expansion of the top and bottom, or note that a and b are constants, and thus are negligible as n increases without bound.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook