Question

点P在曲线y=x³-x+上移动，设点P处切线倾斜角为α，则α的取值范围是

A.［0,］                                 B.［0,)∪［,π)

C.［,π)                                D.(,］

Answer 1

B  ∵y=x³-x+,∴y′=3x²-1≥-1,即在点P处切线的斜率≥-1.∴α∈［0,)∪［,π).