单项选择(2003年全国旧课程

函数f(x)=sinx,x∈[π/2,3π/2]的反函数f-1(x)=【 】

A、-arcsinx,x∈[-1,1]

B、-π-arcsinx,x∈[-1,1

C、π+arcsinx,x∈[-1,1]

D、π-arcsinx,x∈[-1,1]

答案解析

D设x=π+α,由x∈[π/2,3π/2]知α∈[-π/2,π/2],∵y=sinx=sin⁡(π+α)=-sinα,∴α=arcsin⁡(-y)=-arcsiny,∴x=π+α=π-arcsiny,...

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讨论

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