Question

点P在曲线y=x³-x+上移动,在点P处的切线的倾斜角为α,则α的取值范围是

A.［0,］                                    B.(,)

C.［,π)                                     D.(0,］∪［,π)

Answer 1

答案：D

解析:α为倾斜角,则α∈［0,π).y′=3x²-1≥-1,故tanα≥-1,

∴α∈(0,］∪［,π).