Question

若非负实数,a,b满足a+b=10,则根号下a+根号下b≤m恒成立的最小值=

Answer 1

a + b = 10 √a √b ≤ 5

（ √a +√b）^2 = a + b +2√a √b ≤20

即√a +√b≤√20

要使≤m恒成立 m最小为√20 = 2√5