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: Binomial Theorem

  1. Oct 5, 2008 #1
    how do i use binomial to show that 3^k C(n,k) = 3^k 1^n-k C(n,k)
  2. jcsd
  3. Oct 5, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Did you type that correctly? Right now you have stuff = stuff * 1, which is clearly correct...
  4. Oct 5, 2008 #3
    i wanted to explain a bit more
  5. Oct 5, 2008 #4
    It should be
    sum 3^k C(n,k) = 2^2n

    the hint is 3^k C(n,k) = 3^k 1^n-k C(n,k)
  6. Oct 10, 2008 #5


    User Avatar
    Science Advisor

    The reason C(n, k) are called "binomial coefficients" is that C(n, k) is the coefficient of xk in (x+ y)n What are the coefficients of xk in (3x+ y)n? What do you get if x= y= 1?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook