Proving the Binomial Theorem with Induction

AI Thread Summary
The discussion centers on proving the binomial theorem using mathematical induction. The initial approach involves demonstrating the theorem's validity for n=1 and assuming it holds for all n less than n_0, with the goal of proving it for n=n_0+1. The user expresses confusion about completing the proof and seeks guidance. A suggestion is made to utilize Pascal's Triangle, emphasizing that the inductive hypothesis for exponent k can be leveraged to show it holds for k+1 by manipulating the binomial expansion. This method aligns with the approach outlined on the referenced PlanetMath link.
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It seems like this shouldn't be too difficult and yet I'm stumped.
I am trying to prove the binomial theorem.

(x+y)^n = the sum from k=0 to n of (x^k)*(y^n-k)*(The binomial coefficient n,k)

Sorry, about the notation...

Anyway, I figure the best way to go about proving this is by induction.
It is easy to show that its true for n=1.
Then I assume that there exists an n_0 such that it is true for all n < n_0.
Now I want to show that the existence of this n_0 implies that the proposition is also true for n=n_0+1.

This is where I get stuck...
My question is, is this even the best way to go about proving this? If so, how can I finish the proof?

Maybe it would be better to give me a hint so I can figure it out on my own...
 
Mathematics news on Phys.org
http://planetmath.org/encyclopedia/InductiveProofOfBinomialTheorem.html

Go to the above link
 
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What you need to do is look at Pascal's Triangle. You should be aware of the simple procedure required for you to recreate the triangle yourself. You have to show that the number in one spot is equal to the sum of the two numbers above it. Now assume as your inductive hypothesis that the binomial expansion works for the exponent k. To prove that it works for exponent k+1, multiply the assumed expansion for k by just (a - b) (or whatever you are using for the base where the exponent is k), and use the facts just mentioned about Pascal's triangle to show that the expansion takes the desired form for k+1 as well.

EDIT: which is precisely what PlanetMath seems to tell you. :redface:
 
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