1/a+1/b+2√ab的最小值
问题描述：
1/a+1/b+2√ab的最小值
答
1/a+1/b+2√(ab) =(a+b)/(ab)+2√(ab) ≥(2√(ab))/(ab)+2√(ab) =(2/√(ab))+2√(ab) =2[(1/√(ab))+√(ab)] ≥2×2(√[(1/√(ab))×√(ab)]) =4,
1/a+1/b+2√ab的最小值
1/a+1/b+2√(ab) =(a+b)/(ab)+2√(ab) ≥(2√(ab))/(ab)+2√(ab) =(2/√(ab))+2√(ab) =2[(1/√(ab))+√(ab)] ≥2×2(√[(1/√(ab))×√(ab)]) =4,