a,b,c属于R+,求证:1/a+1/b+1/c>=1/根号ab+1/根号bc+1/根号ac
a,b,c属于R+,求证:1/a+1/b+1/c>=1/根号ab+1/根号bc+1/根号ac
日期:2011-10-02 11:31:29 人气:1
a,b,c属于R+,
∴1/a+1/b>=2√(1/a*1/b)=2/√(ab),
同理,1/b+1/c>=2/√(bc),
1/c+1/a>=2/√(ca),
三式相加,除以2,得
1/a+1/b+1/c>=1/√(ab)+1/√(bc)+1/√(ac).