Question

函数f(x)=的最大值为(    )

A.               B.                 C.               D.1

Answer 1

答案：B  f(x)=,x≥0.①当x=0时,f(x)=0.

②当x≠0时,f(x)=,

∵+≥2仅当x=1时取“=”,∴0＜≤,

即0＜f(x)≤.综上:f(x)∈［0,］,故f(x)_max=.