已知a,b,c∈R+,abc=1,求a/(√bc+1)+b/(√ac+1)+c/(√ab+1)的最小值
a+b+c=1≥3(abc)^1/3
abc≤1/27
1/abc≥27
(1/a+1)(1/b+1)(1/c+1)
=1/a+1/b+1/c+1/ab+1/bc+1/ac+1+1/abc≥3(1/abc)^1/3+3
(1/abc)^2/3+1/abc+1=64
所以(1/a+1)(1/b+1)(1/c+1)≥64
得证
是不是弄错题目了……
+1在根号里面吗?