ai>0,i=1,2,...,na_i>0,i=1,2,...,nai>0,i=1,2,...,n其中n∈N+n\in \mathbb{N}^+n∈N+。求证：对于∀k>1,1n∑i=1nai≤1n∑i=1naikk\forall k>1,\frac{1}{n} \sum_{i=1}^{n}a_i \le \sqrt[k]{\frac{1}{n} \sum_{i=1}^{n}a_i^k} ∀k>1,n1∑i=1nai≤kn1∑i=1naik
