Hi my name is Anna and I'm a senior in college. I am a student.

Question: how can I prove that 2nCn is less than 4n, for all positive integers n?
Any help would be greatly appreciated.



One way is toanna1 use the binomial theorem to expand (1+x)2n and note that one of the terms is 2nCnxn; now what happens if you set x = 1?