n^(n+1)与(n+1)^n大小 归纳法
问题描述:
n^(n+1)与(n+1)^n大小 归纳法
再有一个看到了,看是看不懂,给我解释也可以:假设当n=k时(k≥3),结论成立,即kk+1>(k+1)k成立,变形为(kk+k+11)k>1成立,则当n=k+1时,由于kk++21>k+k1,故(k+1)k+2(k+2)k+1=(kk++21)k+1.(k+1)>(k+k1)k+1.(k+1)=(kk+k+11)k>1,即(k+1)k+2>(k+2)k+1
答
你给的答案我也看不懂,我另给答案吧.当n=1时,1^2(k+1)^k,即k^(k+1)/(k+1)^k>1k*(k/(k+1))^k>1当n=k+1时,考察(k+1)^(k+2)>(k+2)^(k+1)是否成立.∵k^2+2k+1>k^2+2k∴(k+1)^2>k(k+2)(k+1)^2/(k+2)>k(k+1)/(k+2)>k/(k+1)...