1.设arc sin([2*2x^(1/2)]/(x+1))=θ显然x>=0,∴x+1>=2*2x^(1/2),(2*2x^(1/2))/(x+1)∈[0,1],θ∈[0,π/2]cosθ>=0cosθ=(1-(sinθ)^2)^(1/2)=abs((x-1)/(x+1))abs是绝对值,最终结果可以讨论,你自己看看吧2.原式=(si...